78 results on '"Chiu JK"'
Search Results
2. The use of rectal balloon during the delivery of intensity modulated radiotherapy (IMRT) for prostate cancer: more than just a prostate gland immobilization device?
- Author
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Teh BS, McGary JE, Dong L, Mai WY, Carpenter LS, Lu HH, Chiu JK, Woo SY, Grant WH, Butler EB, Teh, Bin S, McGary, John E, Dong, Lei, Mai, Wei-Yuan, Carpenter, L Steve, Lu, Hsin H, Chiu, J Kam, Woo, Shiao Y, Grant, Walter H, and Butler, E Brian
- Abstract
Purpose: The purpose of this study was to investigate the role of a rectal balloon for prostate immobilization and rectal toxicity reduction in patients receiving dose-escalated intensity-modulated radiotherapy for prostate cancer.Patients and Methods: Patients with localized prostate cancer who were undergoing intensity-modulated radiotherapy were treated in a prone position, immobilized with a customized Vac-Lok bag (MED-TEC, Orange City, IA). A rectal balloon with 100 cc of air was used to immobilize the prostate. The prostate displacements were measured using computed tomography (CT)-CT fusion on 10 patients who received radioactive seed implant before intensity-modulated radiotherapy. They were scanned twice weekly during 5 weeks of intensity-modulated radiotherapy, and breathing studies were also performed. Rectal toxicity was evaluated by use of Radiation Therapy Oncology Group scoring in 100 patients. They were treated to a mean dose of 76 Gy over 35 fractions (2.17-Gy fraction size). Dose-volume histogram of the rectum was assessed. A film phantom was constructed to simulate the 4-cm diameter air cavity that was created by the rectal balloon. Kodak XV2 films (Rochester NY) were used to measure and compare dose distribution with and without the air cavity. A fraction of 1.25 Gy was delivered to the phantom at isocenter with 15-MV photons by use of the NOMOS Peacock system and the MIMiC treatment delivery system (Sewickley, PA).Results: The anterior-posterior and lateral prostate displacements were minimal, on the order of measurement uncertainty (approximately 1 mm). The standard deviation of superior-inferior displacement was 1.78 mm. Breathing studies showed no organ displacement during normal breathing when the rectal balloon was in place. The rectal toxicity profile was very favorable: 83% (83/100) patients had no rectal complaint, and 11% and 6% had grade 1 and 2 toxicity, respectively. Dose-volume histogram analysis revealed that in all of the patients, no more than 25% of the rectum received 70 Gy or greater. As visualized by film dosimetry, the dose at air-tissue interface was approximately 15% lower than that without an air cavity. The dose built up rapidly so that at 1 and 2 mm, the differential was approximately 8% and 5%, respectively. The dosimetric coverage at the depth of the posterior prostate wall was essentially equal, with or without the air cavity.Discussion: The use of a rectal balloon during intensity-modulated radiotherapy significantly reduces prostate motion. Prostate immobilization thus allows a safer and smaller planning target volume margin. It has also helped spare the anterior rectal wall (by its dosimetric effects) and reduced the rectal volume that received high-dose radiation (by rectal wall distension). All these factors may have further contributed to the decreased rectal toxicity achieved by intensity-modulated radiotherapy, despite dose escalation and higher-than-conventional fraction size. [ABSTRACT FROM AUTHOR]- Published
- 2002
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3. A nociceptive amygdala-striatal pathway for chronic pain aversion.
- Author
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Wojick JA, Paranjapye A, Chiu JK, Mahmood M, Oswell C, Kimmey BA, Wooldridge LM, McCall NM, Han A, Ejoh LL, Chehimi SN, Crist RC, Reiner BC, Korb E, and Corder G
- Abstract
The basolateral amygdala (BLA) is essential for assigning positive or negative valence to sensory stimuli. Noxious stimuli that cause pain are encoded by an ensemble of noci ceptive BLA projection neurons (BLA
noci ensemble). However, the role of the BLAnoci ensemble in mediating behavior changes and the molecular signatures and downstream targets distinguishing this ensemble remain poorly understood. Here, we show that the same BLAnoci ensemble neurons are required for both acute and chronic neuropathic pain behavior. Using single nucleus RNA-sequencing, we characterized the effect of acute and chronic pain on the BLA and identified enrichment for genes with known functions in axonal and synaptic organization and pain perception. We thus examined the brain-wide targets of the BLAnoci ensemble and uncovered a previously undescribed noci ceptive hotspot of the nucleus accumbens shell (NAcSh) that mirrors the stability and specificity of the BLAnoci ensemble and is recruited in chronic pain. Notably, BLAnoci ensemble axons transmit acute and neuropathic noci ceptive information to the NAcSh, highlighting this noci ceptive amygdala-striatal circuit as a unique pathway for affective-motivational responses across pain states., Competing Interests: B.C.R. receives research funding from Novo Nordisk and Boehringer Ingelheim that was not used in support of these studies. The other authors declare no competing interests.- Published
- 2024
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4. A Scalable Open-Set ECG Identification System Based on Compressed CNNs.
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Wu SC, Wei SY, Chang CS, Swindlehurst AL, and Chiu JK
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- Humans, Algorithms, Biometry, Electrocardiography, Neural Networks, Computer, Biometric Identification
- Abstract
Deep learning (DL) is known for its excellence in feature learning and its ability to deliver high-accuracy results. Its application to ECG biometric recognition has received increasing interest but is also accompanied by several deficiencies. In this study, we focus on applying DL, especially convolutional neural networks (CNNs), to ECG biometric identification to address these deficiencies. Using prestored user-specific feature vectors, the proposed scheme can exclude unregistered subjects to realize "open-set" identification. With the help of its scalable structure and "transfer learning," new subjects can be enrolled in an existing system without the need for storing the ECGs of those previously enrolled. Finally, schemes based on the quantum evolutionary algorithm (QEA) are presented to prune unnecessary filters in the proposed CNN model. The performance of the proposed scheme was evaluated using the ECGs of 285 subjects from the PTB dataset. The experimental results demonstrate an identification rate of more than 99% in closed-set identification. Although incorporating the proposed method for unregistered subject exclusion degraded the identification performance slightly, the ability of the approach to resist a dictionary attack was evident. Finally, using the QEA-based filter pruning method and its two-stage extension reduced the number of floating-point operations required to complete one identity recognition to 1.20% and 0.22% of the original value without significantly impacting the identification accuracy.
- Published
- 2023
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5. A Scalable ECG Identification System Based on Locality-Sensitive Hashing.
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Chu HY, Lin TY, Lee SH, Chiu JK, Nien CP, and Wu SC
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- Humans, Electrocardiography, Phenotype, Recognition, Psychology, Algorithms, Biometric Identification
- Abstract
Electrocardiograms (ECGs) have the inherent property of being intrinsic and dynamic and are shown to be unique among individuals, making them promising as a biometric trait. Although many ECG biometric recognition approaches have demonstrated accurate recognition results in small enrollment sets, they can suffer from performance degradation when many subjects are enrolled. This study proposes an ECG biometric identification system based on locality-sensitive hashing (LSH) that can accommodate a large number of registrants while maintaining satisfactory identification accuracy. By incorporating the concept of LSH, the identity of an unknown subject can be recognized without performing vector comparisons for all registered subjects. Moreover, a kernel density estimator-based method is used to exclude unregistered subjects. The ECGs of 285 subjects from the PTB dataset were used to evaluate the proposed scheme's performance. Experimental results demonstrated an IR and EER of 99% and 4%, respectively, when N
en /Nid = 15/3.- Published
- 2023
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6. ECG-based Biometric Recognition without QRS Segmentation: A Deep Learning-Based Approach.
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Chiu JK, Chang CS, and Wu SC
- Subjects
- Algorithms, Biometry, Electrocardiography, Humans, Biometric Identification, Deep Learning
- Abstract
Electrocardiogram (ECG)-based identification systems have been widely studied in the literature. Usually, an ECG trace needs to be segmented according to the detected R peaks to enable feature extraction from the ECGs of duration equal to nearly one cardiac cycle. Beat averaging should also be applied to reduce the influence of inter-beat variation on the extracted features and identification accuracy. Either detecting R peaks or collecting extra heartbeats for averaging will inevitably lead to a delay in the identification process. This paper proposes a deep learning-based ECG biometric identification scheme that allows identity recognition using a random ECG segment without needing R-peak detection and beat averaging. Moreover, the problem of being vulnerable to unregistered subjects in an identification system is also addressed. Experimental results demonstrated that an identification rate of 99.1% for an identification system having 235 enrollees with an equal error rate of 8.08% was achieved.
- Published
- 2021
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7. A comprehensive study of RNA secondary structure alignment algorithms.
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Chiu JK and Chen YP
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- Base Sequence, Nucleic Acid Conformation, RNA, Sequence Alignment, Sequence Analysis, RNA, Algorithms
- Abstract
RNA secondary structure alignment has received more attention since the discovery of the structure-function relationships in some non-protein-encoding RNAs. However, unlike the pure sequence alignment problem, which has been solved in polynomial time, secondary structure alignment incorporates the base pairings as another information dimension in addition to the base sequence. This problem therefore becomes more challenging. In this study, we classify the selected approaches, and algorithmically illustrate how these methods address the alignment problems with different structure types. Other features such as the types of base pair edit operations supported and the time complexity are also compared., (© The Author 2016. Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.)
- Published
- 2017
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8. Pairwise RNA secondary structure alignment with conserved stem pattern.
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Chiu JK and Chen YP
- Subjects
- Nucleic Acid Conformation, Sequence Alignment, Sequence Analysis, RNA methods, Software, Algorithms, RNA, Untranslated chemistry
- Abstract
Motivation: The regulatory functions performed by non-coding RNAs are related to their 3D structures, which are, in turn, determined by their secondary structures. Pairwise secondary structure alignment gives insight into the functional similarity between a pair of RNA sequences. Numerous exact or heuristic approaches have been proposed for computational alignment. However, the alignment becomes intractable when arbitrary pseudoknots are allowed. Also, since non-coding RNAs are, in general, more conserved in structures than sequences, it is more effective to perform alignment based on the common structural motifs discovered., Results: We devised a method to approximate the true conserved stem pattern for a secondary structure pair, and constructed the alignment from it. Experimental results suggest that our method identified similar RNA secondary structures better than the existing tools, especially for large structures. It also successfully indicated the conservation of some pseudoknot features with biological significance. More importantly, even for large structures with arbitrary pseudoknots, the alignment can usually be obtained efficiently., Availability and Implementation: Our algorithm has been implemented in a tool called PSMAlign. The source code of PSMAlign is freely available at http://homepage.cs.latrobe.edu.au/ypchen/psmalign/., (© The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2015
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9. Efficient conversion of RNA pseudoknots to knot-free structures using a graphical model.
- Author
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Chiu JK and Chen YP
- Subjects
- Algorithms, RNA, Untranslated genetics, Models, Molecular, Nucleic Acid Conformation, RNA, Untranslated chemistry, Sequence Analysis, RNA methods
- Abstract
RNA secondary structures are vital in determining the 3-D structures of noncoding RNA molecules, which in turn affect their functions. Computational RNA secondary structure alignment and analysis are biologically significant, because they help identify numerous functionally important motifs. Unfortunately, many analysis methods suffer from computational intractability in the presence of pseudoknots. The conversion of knotted to knot-free secondary structures is an essential preprocessing step, and is regarded as pseudoknot removal. Although exact methods have been proposed for this task, their computational complexities are undetermined, and so their efficiencies in processing complex pseudoknots are currently unknown. We transformed the pseudoknot removal problem into a circle graph maximum weight independent set (MWIS) problem, in which each MWIS represents a unique optimal deknotted structure. An existing circle graph MWIS algorithm was extended to report either single or all solutions. Its time complexity depends on the number of MWISs, and is guaranteed to report one solution in polynomial time. Experimental results suggest that our extended algorithm is much more efficient than the state-of-the-art tool. We also devised a novel concept called the structural scoring function, and investigated its effectiveness in more accurate solution candidate selection for a certain criteria.
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- 2015
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10. Predicting walking function of patients one month poststroke using modified Rivermead mobility index on admission.
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Shum ST, Chiu JK, Tsang CP, Wong CH, Tsang RC, Ma SL, Ho YL, and Tsang P
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- Aged, Aged, 80 and over, Female, Hospitalization, Humans, Male, Middle Aged, Predictive Value of Tests, Risk Assessment methods, Sensitivity and Specificity, Time Factors, Mobility Limitation, Patient Discharge standards, ROC Curve, Stroke complications, Stroke physiopathology, Walking
- Abstract
Being able to predict walking ability of patients with stroke at an early stage is useful in formulating realistic rehabilitation goals and facilitating early discharge planning, which are beneficial not only to the patients but their family members and health care providers. This study aimed to use the modified Rivermead mobility index (MRMI) of the stroke patients on day 3 of their admission to predict their independent walking ability on day 28 postadmission. A total of 232 patients with acute stroke who were admitted to the acute hospital were recruited. Fifty-three percent of them (n = 123) were able to achieve independent walking ability after 28 days of admission whereas 47.0% of them (n = 109) failed to do so. The receiver operating characteristics curve analysis was performed. The optimal cutoff score with the highest sum of sensitivity and specificity was found to be 18.5 (sensitivity, 85.0%; specificity, 75.0%) and the area under the curve was .880. In conclusion, MRMI on day 3 of admission maybe useful in predicting independent walking ability 1 month after stroke., (Copyright © 2014 National Stroke Association. Published by Elsevier Inc. All rights reserved.)
- Published
- 2014
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11. Chinese adaptation and validation of the patellofemoral pain severity scale.
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Cheung RT, Ngai SP, Lam PL, Chiu JK, and Fung EY
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- Adult, Female, Humans, Male, Patellofemoral Pain Syndrome physiopathology, Reproducibility of Results, Severity of Illness Index, Translations, Pain Measurement methods, Patellofemoral Pain Syndrome diagnosis
- Abstract
Objective: This study validated the Patellofemoral Pain Severity Scale translated into Chinese., Design and Setting: The Chinese Patellofemoral Pain Severity Scale was translated from the original English version following standard forward and backward translation procedures recommended by the International Society for Pharmacoeconomics and Outcomes Research. The survey was then conducted in clinical settings by a questionnaire comprising the Chinese Patellofemoral Pain Severity Scale, Kujala Scale and Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index., Subjects: Eighty-four Chinese reading patients with patellofemoral pain were recruited from physical therapy clinics., Main Measures: Internal consistency of the translated instrument was measured by Cronbach alpha. Convergent validity was examined by Spearman rank correlation coefficient (rho) tests by comparing its score with the validated Chinese version of the Kujala Scale and the WOMAC Osteoarthritis Index while the test-retest reliability was evaluated by administering the questionnaires twice., Results: Cronbach alpha values of individual questions and their overall value were above 0.85. Strong association was found between the Chinese Patellofemoral Pain Severity Scale and the Kujala Scale (rho = -0.72, p < 0.001). Moderate correlation was also found between Chinese Patellofemoral Pain Severity Scale with the WOMAC Osteoarthritis Index (rho = 0.63, p < 0.001). Excellent test-retest reliability (Intraclass correlation coefficient = 0.98) was demonstrated., Conclusions: The Chinese translated version of the Patellofemoral Pain Severity Scale is a reliable and valid instrument for patients with patellofemoral pain.
- Published
- 2013
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12. Validation and reliability of the Physical Activity Scale for the Elderly in Chinese population.
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Ngai SP, Cheung RT, Lam PL, Chiu JK, and Fung EY
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- Age Factors, Aged, Aged, 80 and over, Body Mass Index, China, Cross-Sectional Studies, Female, Humans, Male, Psychometrics, Reproducibility of Results, Statistics, Nonparametric, Surveys and Questionnaires, Geriatric Assessment methods, Geriatrics, Motor Activity physiology
- Abstract
Objectives: Physical Activity Scale for the Elderly (PASE) is a widely used questionnaire in epidemiological studies for assessing the physical activity level of elderly. This study aims to translate and validate PASE in Chinese population., Design: Cross-sectional study., Subjects: Chinese elderly aged 65 or above., Methods: The original English version of PASE was translated into Chinese (PASE-C) following standardized translation procedures. Ninety Chinese elderly aged 65 or above were recruited in the community. Test-retest reliability was determined by comparing the scores obtained from two separate administrations by the intraclass correlation coefficient. Validity was evaluated by Spearman's rank correlation coefficients between PASE and Medical Outcome Survey 36-Item Short Form Health Survey (SF-36), grip strength, single-leg-stance, 5 times sit-to-stand and 10-m walk., Results: PASE-C demonstrated good test-retest reliability (intraclass correlation coefficient = 0.81). Fair to moderate association were found between PASE-C and most of the subscales of SF-36 (rs = 0.285 to 0.578, p < 0.01), grip strength (rs = 0.405 to 0.426, p < 0.001), single-leg-stance (rs = 0.470 to 0.548, p < 0.001), 5 times sit-to-stand (rs = -0.33, p = 0.001) and 10-m walk (rs = -0.281, p = 0.007)., Conclusion: PASE-C is a reliable and valid instrument for assessing the physical activity level of elderly in Chinese population.
- Published
- 2012
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13. The effects of quadriceps strengthening on pain, function, and patellofemoral joint contact area in persons with patellofemoral pain.
- Author
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Chiu JK, Wong YM, Yung PS, and Ng GY
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- Adolescent, Adult, Female, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Muscle Strength Dynamometer, Pain Measurement, Patellofemoral Joint pathology, Prospective Studies, Young Adult, Muscle Strength physiology, Patellofemoral Pain Syndrome rehabilitation, Quadriceps Muscle physiology, Resistance Training
- Abstract
Objective: Patellar malalignment is a major cause of patellofemoral pain syndrome (PFPS), but the relationship between clinical symptoms and changes in patellar position and knee muscle strength has not been confirmed. This study examined the effect of weight training on hip and knee muscle strength, patellofemoral joint contact area, and patellar tilt on subjects with and without PFPS, hoping to develop an optimal rehabilitation protocol for subjects with PFPS., Design: The study uses a prospective independent group comparison. Fifteen subjects with and without PFPS were assessed for knee strength, patellofemoral joint contact area, and patellar tilt angle using magnetic resonance imaging. The subjects with PFPS were also examined and given a numeric pain rating score and a Kujala patellofemoral score. The subjects performed lower-limb weight training 3 times/wk for 8 wks, and the outcomes were assessed both before and after training., Results: Subjects with PFPS have increased their patellofemoral joint contact area after weight training (P < 0.001). No statistical significant change was found on the patellar tilt angle. The isometric and isokinetic knee strength in subjects with and without PFPS have increased after weight training (P value increased from 0.007 to 0.05). Both numeric pain rating and Kujala patellofemoral score in the PFPS group improved after training (P < 0.001)., Conclusions: Weight-training exercise increased knee muscle strength and the patellofemoral joint contact area, which could reduce mechanical stress in the joint, improving pain and function in subjects with PFPS.
- Published
- 2012
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14. Chinese translation and validation of the Kujala scale for patients with patellofemoral pain.
- Author
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Cheung RT, Ngai SP, Lam PL, Chiu JK, and Fung EY
- Subjects
- Adolescent, Adult, Cross-Cultural Comparison, Disability Evaluation, Female, Humans, Language, Male, Middle Aged, Outcome Assessment, Health Care, Pain Measurement, Patellofemoral Joint physiopathology, Patellofemoral Pain Syndrome psychology, Psychometrics methods, Quality of Life, Reproducibility of Results, Young Adult, Patellofemoral Pain Syndrome physiopathology, Psychometrics standards, Surveys and Questionnaires standards, Translations
- Abstract
Purpose: This study translated and validated the Kujala scale, a well-documented questionnaire for patients with patellofemoral pain, into Chinese version., Method: Chinese Kujala scale was translated from the original English version following the recommendations of the International Society for Pharmacoeconomics and Outcomes Research. Sixty four Chinese reading patients who are diagnosed of patellofemoral pain were recruited from multiple hospitals and physiotherapy clinics. Psychometric property was evaluated in terms of test-retest reliability and internal consistency. Convergent validity was examined by Spearman rank correlation coefficient tests by comparing its score with the validated Chinese version of WOMAC Osteoarthritis Index and SF-36., Results: Chinese Kujala scale demonstrated excellent reliability (ICC = 0.968, p < 0.001). Cronbach's α of individual questions and its overall value were above 0.7. Strong correlation was found between the Chinese Kujala scale and the WOMAC Osteoarthritis Index (rho = -0.708, p < 0.001). Fairly weak correlations were also found between Chinese Kujala scale with the "physical" (rho = 0.413-0.498, p < 0.001) and "energy vitality" (rho = 0.290, p = 0.02) domains of SF-36. However, the relationship between the "bodily pain" was not significant (rho = 0.136, p = 0.284)., Conclusion: The Chinese translated version of Kujala scale is a reliable and valid instrument for assessing the patellofemoral pain associated functional disturbances among the patient cohort.
- Published
- 2012
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15. Conformational features of topologically classified RNA secondary structures.
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Chiu JK and Chen YP
- Subjects
- Algorithms, Computational Biology methods, Models, Molecular, Nucleic Acid Conformation, RNA chemistry
- Abstract
Background: Current RNA secondary structure prediction approaches predict prevalent pseudoknots such as the H-pseudoknot and kissing hairpin. The number of possible structures increases drastically when more complex pseudoknots are considered, thus leading to computational limitations. On the other hand, the enormous population of possible structures means not all of them appear in real RNA molecules. Therefore, it is of interest to understand how many of them really exist and the reasons for their preferred existence over the others, as any new findings revealed by this study might enhance the capability of future structure prediction algorithms for more accurate prediction of complex pseudoknots., Methodology/principal Findings: A novel algorithm was devised to estimate the exact number of structural possibilities for a pseudoknot constructed with a specified number of base pair stems. Then, topological classification was applied to classify RNA pseudoknotted structures from data in the RNA STRAND database. By showing the vast possibilities and the real population, it is clear that most of these plausible complex pseudoknots are not observed. Moreover, from these classified motifs that exist in nature, some features were identified for further investigation. It was found that some features are related to helical stacking. Other features are still left open to discover underlying tertiary interactions., Conclusions: Results from topological classification suggest that complex pseudoknots are usually some well-known motifs that are themselves complex or the interaction results of some special motifs. Heuristics can be proposed to predict the essential parts of these complex motifs, even if the required thermodynamic parameters are currently unknown.
- Published
- 2012
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16. Ultrasensitive electrochemical detection of biotin using electrically addressable site-oriented antibody immobilization approach via aminophenyl boronic acid.
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Ho JA, Hsu WL, Liao WC, Chiu JK, Chen ML, Chang HC, and Li CC
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- Animals, Antibodies, Immobilized, Biosensing Techniques statistics & numerical data, Boronic Acids, Electrochemical Techniques, Gold, Graphite, Humans, Immunoassay statistics & numerical data, Liposomes, Metal Nanoparticles, Mice, Nanotechnology, Sensitivity and Specificity, Biosensing Techniques methods, Biotin analysis, Biotin immunology, Immunoassay methods
- Abstract
A common approach towards developing immunoassays is to attach antibodies onto the surfaces of assay devices via a solid support. When directly adsorbed onto surfaces, however, antibodies generally adopt random orientations and therefore, often fail to exhibit their immunoaffinity. To preserve the antigen-binding activity of antibodies, there is an urgent need to develop specific and novel linking chemistries for attaching the antibodies to the solid surfaces in an oriented manner. In this paper, we report 2 alternative immobilization methods to enhance the orientation of antibodies onto screen-printed graphite electrodes (SPGEs). The first approach involves the deposition of gold nanoparticles (AuNPs) onto the SPGE and subsequent adsorption of monovalent half-antibody (monoAb) fragments of the anti-biotin antibody via Au-thiol bonds. For the second technique, we exploited the affinity of boronic acid towards sugar moieties by preparing a boronic acid-presenting SPGE surface to interact with the carbohydrate unit of this anti-biotin antibody. Using such approaches, we prepared an ultrasensitive electrochemical immunosensor, possessing a maximized epitope density, for the detection of biotin at concentrations as low as 0.19pg., (Copyright © 2010 Elsevier B.V. All rights reserved.)
- Published
- 2010
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17. Gold-nanostructured immunosensor for the electrochemical sensing of biotin based on liposomal competitive assay.
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Ho JA, Chiu JK, Hong JC, Lin CC, Hwang KC, and Hwu JR
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- Antibodies chemistry, Antibodies immunology, Biosensing Techniques instrumentation, Biotin chemical synthesis, Biotin immunology, Electrochemistry instrumentation, Electrochemistry methods, Electrodes, Ferrocyanides chemistry, Immunoassay instrumentation, Liposomes chemical synthesis, Nanostructures ultrastructure, Polyamines chemical synthesis, Polyamines chemistry, Sensitivity and Specificity, Biosensing Techniques methods, Biotin analysis, Gold chemistry, Immunoassay methods, Liposomes chemistry, Nanostructures chemistry
- Abstract
This work describes the development of a cost-effective, easy-to-use, portable immunoanalytical platform technology with sufficient sensitivity for use in the detection of physiologically important targets. Biotin, also known as vitamin H, was selected as the model analyte. The detecting system employs biotin-tagged, potassium ferrocyanide-encapsulated liposomes as the signal amplifier and PAH (poly allylamine hydrochloride)-modified, nanosized-Au particles assembled screen-printed electrode (nanoAu-SPE) as the working electrode. The diagnostic procedures are based on selective immunoanalytical recognitions and sensitive electrochemical detection. The model analyte biotin was determined based on a "competitive-type" immunoassay in which competition occurs between the analyte biotin and potassium ferrocyanide-encapsulated, biotin-tagged liposomes for a limited number of anti-biotin antibody binding sites, which were immobilized on the PAH/nanoAu/SPE surface. The nanostructured Au SPE surface was covalently bonded to the PAH layer, which subsequently interacted with anti-biotin antibodies. The ferrocyanide released from ruptured bound-liposomes was finally measured using square-wave voltammetry. The calibration curve for biotin had a linear range of 10(-11)-10(-2) M, covering nine orders of magnitude. The detection limit of this immunodetecting system was as low as 9.1 pg of biotin (equivalent to 4.5/microL of 8.3 x 10(-9) M).
- Published
- 2009
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18. Intensity-modulated radiation therapy in childhood ependymoma.
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Schroeder TM, Chintagumpala M, Okcu MF, Chiu JK, Teh BS, Woo SY, and Paulino AC
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- Adolescent, Adult, Brain Neoplasms diagnosis, Child, Child, Preschool, Dose-Response Relationship, Radiation, Ependymoma diagnosis, Female, Humans, Infant, Male, Neoplasm Recurrence, Local diagnosis, Radiotherapy Dosage, Retrospective Studies, Treatment Outcome, Brain Neoplasms radiotherapy, Ependymoma radiotherapy, Neoplasm Recurrence, Local prevention & control, Neoplasm Recurrence, Local radiotherapy, Radiotherapy, Conformal methods
- Abstract
Purpose: To determine the patterns of failure after intensity-modulated radiation therapy (IMRT) for localized intracranial ependymoma., Methods and Materials: From 1994 to 2005, 22 children with pathologically proven, localized, intracranial ependymoma were treated with adjuvant IMRT. Of the patients, 12 (55%) had an infratentorial tumor and 14 (64%) had anaplastic histology. Five patients had a subtotal resection (STR), as evidenced by postoperative magnetic resonance imaging. The clinical target volume encompassed the tumor bed and any residual disease plus margin (median dose 54 Gy). Median follow-up for surviving patients was 39.8 months., Results: The 3-year overall survival rate was 87% +/- 9%. The 3-year local control rate was 68% +/- 12%. There were six local recurrences, all in the high-dose region of the treatment field. Median time to recurrence was 21.7 months. Of the 5 STR patients, 4 experienced recurrence and 3 died. Patients with a gross total resection had significantly better local control (p = 0.024) and overall survival (p = 0.008) than those with an STR. At last follow-up, no patient had developed visual loss, brain necrosis, myelitis, or a second malignancy., Conclusions: Treatment with IMRT provides local control and survival rates comparable with those in historic publications using larger treatment volumes. All failures were within the high-dose region, suggesting that IMRT does not diminish local control. The degree of surgical resection was shown to be significant for local control and survival.
- Published
- 2008
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19. Supine craniospinal irradiation using intrafractional junction shifts and field-in-field dose shaping: early experience at Methodist Hospital.
- Author
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South M, Chiu JK, Teh BS, Bloch C, Schroeder TM, and Paulino AC
- Subjects
- Adolescent, Adult, Atlanto-Occipital Joint, Cerebellar Neoplasms radiotherapy, Child, Child, Preschool, Cranial Irradiation instrumentation, Female, Humans, Male, Mechanics, Medulloblastoma radiotherapy, Neoplasms, Germ Cell and Embryonal radiotherapy, Particle Accelerators instrumentation, Pineal Gland, Pinealoma radiotherapy, Radiotherapy Planning, Computer-Assisted methods, Rhabdoid Tumor radiotherapy, Spine, Teratoma radiotherapy, Treatment Failure, Brain Neoplasms radiotherapy, Cranial Irradiation methods, Spinal Neoplasms radiotherapy, Supine Position
- Abstract
Purpose: To describe our preliminary experience with supine craniospinal irradiation. The advantages of the supine position for craniospinal irradiation include patient comfort, easier access to maintain an airway for anesthesia, and reduced variability of the head tilt in the face mask., Methods and Materials: The cranial fields were treated with near lateral fields and a table angle to match their divergence to the superior edge of the spinal field. The collimator was rotated to match the divergence from the superior spinal field. The spinal fields were treated using a source to surface distance (SSD) technique with the couch top at 100 cm. When a second spinal field was required, the table and collimator were rotated 90 degrees to allow for the use of the multileaf collimator and so the gantry could be rotated to match the divergence of the superior spinal field. The multileaf collimator was used for daily dynamic featherings and field-in-field dose control., Results: With a median follow-up of 20.2 months, five documented failures and no cases of radiation myelitis occurred in 23 consecutive patients. No failures occurred in the junctions of the spine-spine or brain-spine fields. Two failures occurred in the primary site alone, two in the spinal axis alone, and one primary site failure plus distant metastasis. The median time to recurrence was 17 months., Conclusion: The results of our study have shown that supine approach for delivering craniospinal irradiation is not associated with increased relapses at the field junctions. To date, no cases of radiation myelitis have developed.
- Published
- 2008
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20. Versatility of the Novalis system to deliver image-guided stereotactic body radiation therapy (SBRT) for various anatomical sites.
- Author
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Teh BS, Paulino AC, Lu HH, Chiu JK, Richardson S, Chiang S, Amato R, Butler EB, and Bloch C
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Child, Child, Preschool, Female, Humans, Male, Middle Aged, Neoplasms radiotherapy, Radiotherapy, Computer-Assisted instrumentation
- Abstract
Stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) programs to treat brain tumors were implemented when we first acquired the Brainlab Novalis system in 2003. Two years later, we started an extra-cranial stereotactic radio-ablation or more appropriately a stereotactic body radiation therapy (SBRT) program using the Brainlab Novalis image-guided system at The Methodist Hospital in Houston, Texas. We hereby summarize our initial experience with this system in delivering image-guided SBRT to a total of 80 patients during our first year of clinical implementation, from February 2005 to January 2006. Over 100 lesions in more than 20 distinct anatomical sites were treated. These include all levels of spine from cervical, thoracic, lumbar, and sacral lesions. Spinal lesions encompass intramedullary, intradural, extradural, or osseous compartments. Also treated were lesions in other bony sites including orbit, clavicle, scapula, humerus, sternum, rib, femur, and pelvis (ilium, ischium, and pubis). Primary or metastatic lesions located in the head and neck, supraclavicular region, axilla, mediastinum, lung (both central and peripheral), abdominal wall, liver, kidney, para-aortic lymph nodes, prostate, and pelvis were also treated. In addition to primary radiotherapy, SBRT program using the Brainlab Novalis system allows re-irradiation for recurrence and "boost" after conventional treatment to various anatomical sites. Treating these sites safely and efficaciously requires knowledge in radiation tolerance, fraction size, total dose, biologically equivalent dose (BED), prior radiotherapy, detailed dose volume histograms (DVH) of normal tissues, and the radiosensitive/radioresistant nature of the tumor. Placement of radio-opaque markers (Visicoil, Radiomed) in anatomical sites not in close proximity to bony landmarks (e.g., kidney and liver) helps in measuring motion and providing image guidance during each treatment fraction. Tumor/organ motion data obtained using 4D-CT while the patient is immobilized in the body cast aids in planning treatment margin and determining the need for respiratory motion control, e.g., abdominal compressor, gating, or active breathing control. The inclusion of PET/CT to the Brainlab treatment planning system further refines the target delineation and possibly guides differential fraction size prescription and delivery. The majority of the patients tolerated the SBRT treatment well despite the longer daily treatment time when compared to that of conventional treatment. All patients achieved good pain relief after SBRT. Compared to conventional standard radiotherapy of lower daily fraction size, we observed that the patients achieved faster pain relief and possibly more durable symptom control. Very high local control with stable disease on imaging was observed post SBRT. Our initial experience shows that the Brainlab Novalis system is very versatile in delivering image-guided SBRT to various anatomical sites. This SBRT approach can be applied to either primary or metastatic lesions in the primary, "boost," or re-irradiation settings. The understanding of fraction size, total dose, BED, and DVH of normal tissues is very important in the treatment planning. Appropriate use of immobilization devices, radio-opaque markers for image-guidance, 4D-CT for tumor/organ motion estimates, and fusion of planning CT scans with biological/functional imaging will further improve the planning and delivery of SBRT, hopefully leading to better treatment outcome.
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- 2007
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21. Phase I-II trial evaluating combined intensity-modulated radiotherapy and in situ gene therapy with or without hormonal therapy in treatment of prostate cancer-interim report on PSA response and biopsy data.
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Teh BS, Ayala G, Aguilar L, Mai WY, Timme TL, Vlachaki MT, Miles B, Kadmon D, Wheeler T, Caillouet J, Davis M, Carpenter LS, Lu HH, Chiu JK, Woo SY, Thompson T, Aguilar-Cordova E, and Butler EB
- Subjects
- Acyclovir therapeutic use, Adenoviridae genetics, Adult, Aged, Aged, 80 and over, Androgen Antagonists therapeutic use, Antineoplastic Agents, Hormonal therapeutic use, Antiviral Agents therapeutic use, Biopsy, Combined Modality Therapy, Flutamide therapeutic use, Follow-Up Studies, Genetic Vectors therapeutic use, Humans, Leuprolide therapeutic use, Male, Middle Aged, Prodrugs therapeutic use, Prostate pathology, Prostatic Neoplasms pathology, Radiotherapy Dosage, Thymidine Kinase genetics, Valacyclovir, Valine therapeutic use, Acyclovir analogs & derivatives, Genetic Therapy methods, Prostate-Specific Antigen blood, Prostatic Neoplasms blood, Prostatic Neoplasms therapy, Radiotherapy, Conformal, Thymidine Kinase therapeutic use, Valine analogs & derivatives
- Abstract
Purpose: There is an evolving role for combining radiotherapy (RT) with gene therapy in the management of prostate cancer. However, the clinical results of this combined approach are much needed. The preliminary results addressing the safety of this Phase I-II study combining RT and gene therapy (adenovirus/herpes simplex virus-thymidine kinase gene/valacyclovir with or without hormonal therapy) in the treatment of prostate cancer have been previously reported. We now report the prostate-specific antigen (PSA) response and biopsy data., Methods and Materials: This trial was composed of three separate arms. Arm A consisted of low-risk patients (Stage T1-T2a, Gleason score <7, pretreatment PSA <10 ng/mL) treated with combined RT-gene therapy. A mean dose of 76 Gy was delivered to the prostate with intensity-modulated RT. They also received adenovirus/herpes simplex virus-thymidine kinase/valacyclovir gene therapy. Arm B consisted of high-risk patients (Stage T2b-T3, Gleason score >6, pretreatment PSA level >10 ng/mL) treated with combined RT-gene therapy and hormonal therapy (luteinizing hormone-releasing hormone agonist [30-mg Lupron, 4-month depot] and an antiandrogen [flutamide, 250 mg t.i.d. for 14 days]). Arm C consisted of patients with Stage D1 (positive pelvic lymph nodes) who received the same regimen as Arm B with the addition of 45 Gy to the pelvic lymphatics. PSA determination and biopsy were performed before, during, and after treatment. The American Society for Therapeutic Radiology and Oncology consensus definition (three consecutive rises in PSA level) was used to denote PSA failure., Results: Fifty-nine patients (29 in Arm A, 26 in Arm B, and 4 in Arm C) completed the trial. The median age was 68 years (range, 39-85 years). The median follow-up for the entire group was 13.5 months (range, 1.4-27.8 months). Only Arm A patients were observed to have an increase in PSA on Day 14. The PSA then declined appropriately. All patients in Arm A (median follow-up, 13.4 months) and Arm B (median follow-up, 13.9 months) had biochemical control at last follow-up. Three patients in Arm C (with pretreatment PSA of 335, 19.6, and 2.5 ng/mL and a combined Gleason score of 8, 9, and 9 involving all biopsy cores) had biochemical failure at 3, 3, and 7.7 months. Two patients had distant failure in bone and 1 patient in the para-aortic lymph nodes outside the RT portal. Six to twelve prostate biopsies performed in these 3 patients revealed no evidence of residual carcinoma. In Arm A, biopsy showed no evidence of carcinoma in 66.7% (18 of 27), 92.3% (24 of 26), 91.7% (11 of 12), 100% (8 of 8), and 100% (6 of 6) at 6 weeks, 4 months, 12 months, 18 months, and 24 months after treatment, respectively. In Arm B, no evidence of carcinoma on biopsy was noted in 96% (24 of 25), 90.5% (19 of 21), 100% (14 of 14), 100% (7 of 7), and 100% (2 of 2), respectively, in the same interval after treatment., Conclusion: This is the first reported trial of its kind in the field of prostate cancer that aims to expand the therapeutic index of RT by combining it with in situ gene therapy. The initial transient PSA rise in the Arm A patients may have been a result of local immunologic response or inflammation elicited by in situ gene therapy. Additional investigation to elucidate the mechanisms is needed. Hormonal therapy may have obliterated this rise in Arm B and C patients. The biopsy data were encouraging and appeared to show no evidence of malignancy earlier than historical data. Combined RT, short-course hormonal therapy, and in situ therapy appeared to provide good locoregional control but inadequate systemic control in patients with positive pelvic lymph nodes. Longer term use of hormonal therapy in addition to gene therapy and RT has been adopted for this group of patients to maximize both locoregional and systemic control.
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- 2004
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22. Initial experience using intensity-modulated radiotherapy for recurrent nasopharyngeal carcinoma.
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Lu TX, Mai WY, Teh BS, Zhao C, Han F, Huang Y, Deng XW, Lu LX, Huang SM, Zeng ZF, Lin CG, Lu HH, Chiu JK, Carpenter LS, Grant WH 3rd, Woo SY, Cui NJ, and Butler EB
- Subjects
- Adult, Aged, Feasibility Studies, Female, Humans, Male, Middle Aged, Radiation Injuries etiology, Radiotherapy Dosage, Radiotherapy Planning, Computer-Assisted, Nasopharyngeal Neoplasms radiotherapy, Neoplasm Recurrence, Local radiotherapy, Radiotherapy, Conformal methods
- Abstract
Purpose: To report our initial experience on the feasibility, toxicity, and tumor control using intensity-modulated radiotherapy (IMRT) for retreatment of recurrent nasopharyngeal carcinoma (NPC)., Methods and Materials: A total of 49 patients with locoregional recurrent carcinoma in the nasopharynx were treated with IMRT between January 2001 and February 2002 at the Sun Yat-Sen University Cancer Center, Guangzhou, China. The average time to the nasopharyngeal recurrence was 30.2 months after initial conventional RT. The median isocenter dose to the nasopharynx was 70 Gy (range 60.9-78.0) for the initial conventional RT. All patients were restaged at the time of recurrence according to the 1992 Fuzhou, China staging system on NPC. The number of patients with Stage I, II, III and IV disease was 4, 9, 10, and 26, respectively. T1, T2, T3, and T4 disease was found in 4, 9, 11, and 25 patients, respectively. N0, N1, N2, and N3 disease was found in 46, 2, 0, and 1 patient, respectively. Invasion of the nasal cavity, maxillary sinus, ethmoid sinus, sphenoid sinus, and cavernous sinus and erosion of the base of the skull was found in 8, 1, 3, 8, 15, and 20 patients, respectively. The gross tumor volume (GTV) was contoured according to the International Commission on Radiation Units and Measurements (ICRU) Report 62 guidelines. The critical structures were contoured, and the doses to critical structures were constrained according to ICRU 50 guidelines. The GTV in the nasopharynx and positive lymph nodes in the neck received a prescription dose of 68-70 Gy and 60 Gy, respectively. All patients received full-course IMRT. Three patients who had positive lymph nodes were treated with five to six courses of chemotherapy (cisplatin + 5-fluorouracil) after IMRT., Results: The treatment plans showed that the percentage of GTV receiving 95% of the prescribed dose (V(95-GTV)) was 98.5%, and the dose encompassing 95% of GTV (D(95-GTV)) was 68.1 Gy in the nasopharynx. The mean dose to the GTV was 71.4 Gy. The average doses of the surrounding critical structures were much lower than the tolerable thresholds. At a median follow-up of 9 months (range 3-13), the locoregional control rate was 100%. Three cases (6.1%) of locoregional residual disease were seen at the completion of IMRT, but had achieved a complete response at follow-up. Three patients developed metastases at a distant site: two in the bone and one in the liver and lung at 13 months follow-up. Acute toxicity (skin, mucosa, and xerostomia) was acceptable according to the Radiation Therapy Oncology Group criteria. Tumor necrosis was seen toward the end of IMRT in 14 patients (28.6%)., Conclusion: The improvement in tumor target coverage and significant sparing of adjacent critical structures allow the feasibility of IMRT as a retreatment option for recurrent NPC after initial conventional RT. This is the first large series using IMRT to reirradiate local recurrent NPC after initial RT failed. The treatment-related toxicity profile was acceptable. The initial tumor response/local control was also very encouraging. In contrast to primary NPC, recurrent NPC reirradiated with high-dose IMRT led to the shedding of tumor necrotic tissue toward the end of RT. More patients and longer term follow-up are warranted to evaluate late toxicity and treatment outcome.
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- 2004
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23. Hypofractionated intensity-modulated radiotherapy for primary glioblastoma multiforme.
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Floyd NS, Woo SY, Teh BS, Prado C, Mai WY, Trask T, Gildenberg PL, Holoye P, Augspurger ME, Carpenter LS, Lu HH, Chiu JK, Grant WH 3rd, and Butler EB
- Subjects
- Adult, Brain Neoplasms pathology, Dose Fractionation, Radiation, Follow-Up Studies, Glioblastoma pathology, Humans, Middle Aged, Neoplasm Recurrence, Local, Pilot Projects, Survival Analysis, Brain Neoplasms radiotherapy, Glioblastoma radiotherapy, Radiotherapy, Conformal methods
- Abstract
Purpose: A pilot study was designed to evaluate the safety and efficacy of a novel regimen of hypofractionated intensity-modulated radiotherapy (RT) in the adjuvant treatment of primary glioblastoma multiforme (GBM). The rationale of the study was to combine the potential radiobiologic advantage of hypofractionation to GBM with a highly conformal radiotherapeutic technique. The study was designed to measure the acute and chronic morbidity of patients treated with this regimen, response of GBM to the treatment, overall survival, and time to disease progression after therapy completion., Methods and Materials: Twenty eligible patients were accrued between February 1999 and May 2000 for the study. All patients had Karnofsky performance scores of >/=70. All patients were treated with intensity-modulated RT using the NOMOS Peacock system. A dose of 50 Gy was delivered in 5-Gy daily fractions within 2 weeks to enhancing primary disease, residual tumor, or surgical cavity. Simultaneously, 30 Gy was prescribed in 3-Gy daily fractions to surrounding edema. The time to progression was measured with serial neurologic examinations and MRI or CT scans after RT completion. Acute and late toxicity was graded using Radiation Therapy Oncology Group neurotoxicity scores., Results: Of the 20 patients, 18 were evaluated for outcome. The median time to disease progression was 6 months after RT completion. The median overall survival was 7 months after treatment completion. All recurrences were within 2 cm of the operative bed. Neurotoxicity during therapy was minimal, with all patients experiencing Grade 0 or 1 toxicity. Late toxicity included 10 patients with Grade 0, 2 patients with Grade 2, and 3 patients with Grade 4 toxicity, manifesting as brain necrosis requiring surgical reexcision. The survival of the 3 patients with brain necrosis was 23, 20, and 9 months. Mortality in all cases was the result of tumor recurrence, with no mortality resulting from brain necrosis., Conclusion: This regimen of hypofractionated intensity-modulated RT did not improve the time to disease progression or overall survival compared with historical experience using conventional fractionation. However, the treatment duration was reduced from 6 weeks to 2 weeks, which may be of palliative benefit in certain subsets of patients. This treatment regimen demonstrated a greater incidence of brain necrosis requiring surgical intervention; however, the 3 patients experiencing this toxicity had longer survival times. Future investigation may be useful to determine which fraction size may be optimal for GBM when highly conformal RT is used in the adjuvant setting.
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- 2004
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24. Uterine evacuation with misoprostol during radiotherapy for cervical cancer in pregnancy.
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Ostrom K, Ben-Arie A, Edwards C, Gregg A, Chiu JK, and Kaplan AL
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- Adult, Cisplatin therapeutic use, Female, Humans, Pregnancy, Radiation-Sensitizing Agents therapeutic use, Treatment Outcome, Abortifacient Agents, Nonsteroidal therapeutic use, Abortion, Therapeutic methods, Carcinoma, Squamous Cell radiotherapy, Misoprostol therapeutic use, Pregnancy Complications, Neoplastic radiotherapy, Radiotherapy methods, Uterine Cervical Neoplasms radiotherapy
- Abstract
Radiotherapy as definitive treatment for invasive cervical cancer during pregnancy causes spontaneous abortion in most cases. Surgical evacuation of the uterus is indicated when abortion does not occur, exposing patients to additional morbidity. Two Latin American women, diagnosed with FIGO stage IB2 cervical cancer at approximately 15 weeks gestation, underwent radiotherapy with radiosensitizing chemotherapy. After intrauterine fetal demise was detected, both women underwent induction with misoprostol. Results included one complete abortion and one incomplete abortion without complications or delays in treatment. These cases demonstrate that induction with misoprostol appears to be a safe and effective alternative to surgical evacuation of the uterus when spontaneous abortion fails to occur during radiotherapy for locally advanced cervical cancer.
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- 2003
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25. Dosimetric predictors of xerostomia for head-and-neck cancer patients treated with the smart (simultaneous modulated accelerated radiation therapy) boost technique.
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Amosson CM, Teh BS, Van TJ, Uy N, Huang E, Mai WY, Frolov A, Woo SY, Chiu JK, Carpenter LS, Lu HH, Grant WH 3rd, and Butler EB
- Subjects
- Adult, Aged, Deglutition Disorders etiology, Dose Fractionation, Radiation, Dose-Response Relationship, Radiation, Dysgeusia etiology, Feasibility Studies, Female, Follow-Up Studies, Head and Neck Neoplasms diagnostic imaging, Humans, Male, Maximum Tolerated Dose, Middle Aged, Parotid Gland injuries, Patient Acceptance of Health Care, Radiotherapy Planning, Computer-Assisted, Radiotherapy, Conformal instrumentation, Radiotherapy, Conformal methods, Retrospective Studies, Salivation radiation effects, Sleep Wake Disorders etiology, Speech Disorders etiology, Surveys and Questionnaires, Thirst, Tomography, X-Ray Computed, Head and Neck Neoplasms radiotherapy, Parotid Gland radiation effects, Radiation Injuries etiology, Radiometry, Radiotherapy, Conformal adverse effects, Xerostomia etiology
- Abstract
Purpose: To evaluate the predictors of xerostomia in the treatment of head-and-neck cancers treated with intensity-modulated radiation therapy (IMRT), using the simultaneous modulated accelerated radiation therapy (SMART) boost technique. Dosimetric parameters of the parotid glands are correlated to subjective salivary gland function., Materials and Methods: Between January 1996 and June 2000, 30 patients with at least 6 months follow-up were evaluated for subjective xerostomia after being treated definitively for head-and-neck cancer with the SMART boost technique. Threshold limits for the ipsilateral and contralateral parotid glands were 35 Gy and 25 Gy, respectively. Dosimetric parameters to the parotid glands were evaluated. The median follow-up time was 38.5 months (mean 39.9 months). The results of the dosimetric parameters and questionnaire were statistically correlated., Results: Xerostomia was assessed with a 10-question subjective salivary gland function questionnaire. The salivary gland function questionnaire (questions 1, 2, 3, 4, 6, and 9) correlated significantly with the dosimetric parameters (mean and maximum doses and volume and percent above tolerance) of the parotid glands. These questions related to overall comfort, eating, and abnormal taste. Questions related to thirst, difficulty with speech or sleep, and the need to carry water daily did not correlate statistically with the dosimetric parameters of the parotid glands., Conclusions: Questions regarding overall comfort, eating, and abnormal taste correlated significantly with the dosimetric parameters of the parotid glands. Questions related to thirst, difficulty with speech or sleep, and the need to carry water daily did not correlate statistically with the dosimetric parameters of the parotid glands. Dosimetric sparing of the parotid glands improved subjective xerostomia. IMRT in the treatment of head-and-neck cancer can be exploited to preserve the parotid glands and decrease xerostomia. This is feasible even with an accelerated treatment regimen like the SMART boost. More patients need to be evaluated using IMRT to identify relevant dosimetric parameters.
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- 2003
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26. IMRT for prostate cancer: defining target volume based on correlated pathologic volume of disease.
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Teh BS, Bastasch MD, Wheeler TM, Mai WY, Frolov A, Uhl BM, Lu HH, Carpenter LS, Chiu JK, McGary J, Woo SY, Grant WH 3rd, and Butler EB
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- Adenocarcinoma diagnostic imaging, Adenocarcinoma pathology, Adenocarcinoma surgery, Adult, Aged, Combined Modality Therapy, Humans, Male, Middle Aged, Neoplasm Invasiveness, Neoplasm Staging, Prostatectomy, Prostatic Neoplasms diagnostic imaging, Prostatic Neoplasms pathology, Prostatic Neoplasms surgery, Retrospective Studies, Tomography, X-Ray Computed, Adenocarcinoma radiotherapy, Prostatic Neoplasms radiotherapy, Radiotherapy Planning, Computer-Assisted, Radiotherapy, Conformal methods
- Abstract
Purpose: The intensity-modulated radiation therapy (IMRT) treatment planning system generates tightly constricted isodose lines. It is very important to define the margins that are acceptable in the treatment of prostate cancer to maximize the dose escalation and normal tissue avoidance advantages offered by IMRT. It is necessary to take into account subclinical disease and the potential for extracapsular spread. Organ and patient motion as well as setup errors are variables that must be minimized and defined to avoid underdosing the tumor or overdosing the normal tissues. We have addressed these issues previously. The purpose of the study was twofold: to quantify the radial distance of extracapsular extension in the prostatectomy specimens, and to quantify differences between the pathologic prostate volume (PPV), CT-based gross tumor volume (GTV), and planning target volume (PTV)., Materials and Methods: Two related studies were undertaken. A total of 712 patients underwent prostatectomy between August 1983 and September 1995. Pathologic assessment of the radial distance of extracapsular extension was performed. Shrinkage associated with fixation was accounted for with a linear shrinkage factor. Ten patients had preoperative staging studies including a CT scan of the pelvis. The GTV was outlined and volume determined from these CT scans. The PTV, defined as GTV with a 5-mm margin in all dimensions, was then calculated. The Peacock inverse planning system (NOMOS Corp., Sewickley, PA) was used. The PPV, GTV, and PTV were compared for differences and evaluated for correlation., Results: Extracapsular extension (ECE) (i.e., prostatic capsular invasion level 3 [both focal and established]) was found in 299 of 712 patients (42.0%). Measurable disease extending radially outside the prostatic capsule (i.e., ECE level 3 established) was noted in 185 of 712 (26.0%). The median radial extension was 2.0 mm (range 0.50-12.00 mm) outside the prostatic capsule. As a group, 20 of 712 (2.8%) had extracapsular extension of more than 5 mm. In the volumetric comparison and correlation study of the GTV and PTV to the PPV, the average GTV was 2 times larger than the PPV. The average PTV was 4.1 times larger than the PPV., Conclusions: This is the largest series in the literature quantitatively assessing prostatic capsular invasion (i.e., the radial extracapsular extension). It is the first report of a comparison of PPV to CT-planned GTV and PTV. Using patient and prostate immobilization, 5 mm of margin to the GTV in this study provided sufficient coverage of the tumor volume based on data gathered from 712 patients. In the absence of prostate immobilization, additional margins of differing amounts depending on the technique employed would have to be placed to account for target, patient, and setup uncertainties. The large mean difference between CT-based estimates of the tumor volume and target volume (GTV+PTV) and PPV added further evidence for adequacy of tumor coverage. Target immobilization, setup error, and coverage of subclinical disease must be addressed carefully before successful implementation of IMRT to maximize its ability to escalate dose and to spare normal tissue simultaneously and safely.
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- 2003
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27. Using technology to decrease xerostomia for head and neck cancer patients treated with radiation therapy.
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Amosson CM, Teh BS, Mai WY, Woo SY, Chiu JK, Donovan DT, Parke R, Carpenter LS, Lu HH, Grant WH 3rd, and Butler EB
- Subjects
- Adult, Aged, Female, Humans, Male, Middle Aged, Parotid Gland, Quality of Life, Radiation Injuries diagnosis, Radiotherapy Dosage, Surveys and Questionnaires, Xerostomia diagnosis, Xerostomia etiology, Head and Neck Neoplasms radiotherapy, Radiation Injuries prevention & control, Radiotherapy, Conformal, Xerostomia prevention & control
- Abstract
The treatment of head and neck cancer has evolved from conventional fields encompassing large volumes of normal tissue to focused treatment aimed at conforming the dose around the target while avoiding normal tissue. Intensity modulated radiation therapy has changed the way radiation oncologists think about head and neck cancer. Using the concepts of conformal treatment and avoidance, the therapeutic ratio can be improved and technology exploited to the patients' advantage. This is particularly evident with head and neck irradiation, where a common side effect is xerostomia. By decreasing xerostomia through conformal avoidance of the parotid glands, we can improve patient satisfaction and quality of life. In this study, xerostomia is assessed through a subjective salivary gland function questionnaire. This article examines the use of intensity modulated radiation therapy in the treatment of head and neck cancer to decrease xerostomia. The purpose of this article is to evaluate the significance of parotid gland dosimetry in relation to subjective salivary gland function., (Copyright 2002, Elsevier Science (USA). All rights reserved.)
- Published
- 2002
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28. Treatment of acoustic neuroma: stereotactic radiosurgery vs. microsurgery.
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Karpinos M, Teh BS, Zeck O, Carpenter LS, Phan C, Mai WY, Lu HH, Chiu JK, Butler EB, Gormley WB, and Woo SY
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- Adolescent, Adult, Aged, Aged, 80 and over, Cranial Nerves radiation effects, Facial Nerve radiation effects, Female, Humans, Male, Middle Aged, Radiosurgery adverse effects, Time Factors, Treatment Outcome, Brain Neoplasms radiotherapy, Brain Neoplasms surgery, Neuroma, Acoustic radiotherapy, Neuroma, Acoustic surgery, Radiosurgery methods
- Abstract
Purpose: Two major treatment options are available for patients with acoustic neuroma, microsurgery and radiosurgery. Our objective was to compare these two treatment modalities with respect to tumor growth control, hearing preservation, development of cranial neuropathies, complications, functional outcome, and patient satisfaction., Methods and Materials: To compare radiosurgery with microsurgery, we analyzed 96 patients with unilateral acoustic neuromas treated with Leksell Gamma Knife or microsurgery at Memorial Hermann Hospital, Houston, Texas, between 1993 and 2000. Radiosurgery technique involved multiple isocenter (1-30 single fraction fixed-frame magnetic resonance imaging) image-based treatment with a mean dose prescription of 14.5 Gy. Microsurgery included translabyrinthine, suboccipital, and middle fossa approaches with intraoperative neurophysiologic monitoring. Preoperative patient characteristics were similar except for tumor size and age. Patients undergoing microsurgery were younger with larger tumors compared to the radiosurgical group. The tumors were divided into small <2.0 cm, medium 2.0-3.9 cm, or large >4.0 cm. Median follow-up of the radiosurgical group was longer than the microsurgical group, 48 months (3-84 months) vs. 24 months (3-72 months)., Results: There was no statistical significance in tumor growth control between the two groups, 100% in the microsurgery group vs. 91% in the radiosurgery group (p > 0.05). Radiosurgery was more effective than microsurgery in measurable hearing preservation, 57.5% vs. 14.4% (p = 0.01). There was no difference in serviceable hearing preservation between the two groups. Microsurgery was associated with a greater rate of facial and trigeminal neuropathy in the immediate postoperative period and at long-term follow-up. The rate of development of facial neuropathy was significantly higher in the microsurgical group than in the radiosurgical group (35% vs. 0%, p < 0.01 in the immediate postsurgical period and 35.3% vs. 6.1%, p = 0.008, at long-term follow-up). Similarly, the rate of trigeminal neuropathy was significantly higher in the microsurgical group than in the radiosurgical group (17% vs. 0% in the immediate postoperative period, p < 001, and 22% vs. 12.2%, p = 0.009, at long-term follow-up). There was no significant difference in exacerbation of preoperative tinnitus, imbalance, dysarthria, dysphagia, and headache. Patients treated with microsurgery had a longer hospital stay (2-16 days vs. 1-2 days, p < 0.01) and more perioperative complications (47.8% vs. 4.6%, p < 0.01) than did patients treated with radiosurgery. There was no correlation between the microsurgical approach used and postoperative symptoms. There was no difference in the postoperative functioning level, employment, and overall patient satisfaction. There was no correlation between the radiation dose, tumor size, number of isocenters used, and postoperative symptoms in the radiosurgical group., Conclusion: Radiosurgical treatment for acoustic neuroma is an alternative to microsurgery. It is associated with a lower rate of immediate and long-term development of facial and trigeminal neuropathy, postoperative complications, and hospital stay. Radiosurgery yields better measurable hearing preservation than microsurgery and equivalent serviceable hearing preservation rate and tumor growth control.
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- 2002
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29. Post-nerve-sparing prostatectomy, dose-escalated intensity-modulated radiotherapy: effect on erectile function.
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Bastasch MD, Teh BS, Mai WY, Carpenter LS, Lu HH, Chiu JK, Woo SY, Grant WH 3rd, Miles BJ, Kadmon D, and Butler EB
- Subjects
- Aged, Follow-Up Studies, Humans, Male, Middle Aged, Penile Erection radiation effects, Prostatectomy adverse effects, Prostatic Neoplasms physiopathology, Prostatic Neoplasms surgery, Radiotherapy Dosage, Prostatectomy methods, Prostatic Neoplasms radiotherapy
- Abstract
Purpose: The advent of widespread prostate-specific antigen screening has resulted in more younger, potent men being diagnosed with early-stage, organ-confined prostate cancer amenable to definitive surgery. Nerve-sparing prostatectomy is a relatively new surgical advance in the treatment of prostate cancer. Very few data exist on the effect of postoperative radiotherapy (RT) on erectile function after nerve-sparing prostatectomy. They are based on conventional techniques using moderate doses of radiation, 45-54 Gy. Intensity-modulated RT (IMRT) is becoming more widespread because it allows dose escalation with increased sparing of the surrounding normal tissue. We investigated the effect of postprostatectomy, high-dose IMRT on patients' erectile function., Methods and Materials: A review of patient records found 51 patients treated between April 1998 and December 2000 with IMRT after unilateral or bilateral nerve-sparing prostatectomy. The pathologic disease stage in these patients was T2 in 47.4% and T3 in 52.6%. Postoperatively, 4 patients received hormonal ablation consisting of one injection of Lupron Depot (30 mg) 2 months before RT. The median age was 65 years (range 46-77) at the time of RT. The prescribed dose was 64 Gy (range 60-66). The mean dose was 69.6 Gy (range 64.0-72.3). Erectile function was assessed before and after RT by questionnaires. Sexual potency was defined as erectile rigidity adequate for vaginal penetration., Results: Of the 51 patients, 18 (35.3%) maintained their potency and 33 (64.7%) became impotent after nerve-sparing prostatectomy. Patients who underwent bilateral nerve-sparing prostatectomy had higher rates of postoperative potency than did those who underwent unilateral nerve-sparing surgery (72.2% vs. 27.8%; p = 0.025). The follow-up for the entire group was 19.5 months. All 18 patients (100%) who were potent postoperatively remained potent after RT. The median follow-up for the 18 potent patients was 27.2 months, significantly longer than that of the impotent group, 13.0 months (p <0.001)., Conclusion: This is the first report on the effects of dose-escalated IMRT on men who have undergone nerve-sparing prostatectomy. Despite the high dose (mean dose 69.6 Gy) to the prostate bed and nerves, postoperative IMRT had no negative effect on erectile function for the patients who remained potent after nerve-sparing prostatectomy. Longer term follow-up and a larger cohort of patients are warranted to confirm these findings.
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- 2002
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30. Intensity-modulated radiation therapy (IMRT) for meningioma.
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Uy NW, Woo SY, Teh BS, Mai WY, Carpenter LS, Chiu JK, Lu HH, Gildenberg P, Trask T, Grant WH, and Butler EB
- Subjects
- Aged, Aged, 80 and over, Disease-Free Survival, Female, Humans, Male, Middle Aged, Radiometry, Time Factors, Treatment Outcome, Brain Neoplasms radiotherapy, Meningioma radiotherapy, Radiotherapy, Conformal methods
- Abstract
Purpose: To assess the safety and efficacy of intensity-modulated radiation therapy (IMRT) in the treatment of intracranial meningioma., Methods and Materials: Forty patients with intracranial meningioma (excluding optic nerve sheath meningiomas) were treated using IMRT with the NOMOS Peacock system between 1994 and 1999. Twenty-five patients received IMRT after surgery either as adjuvant therapy for incomplete resection or for recurrence, and 15 patients received definitive IMRT after presumptive diagnosis based on imaging. Thirty-two patients had skull base lesions, and 8 had nonskull base lesions. The prescribed dose ranged from 40 to 56 Gy (median 50.4 Gy) at 1.71 to 2 Gy per fraction, and the volume of the primary target ranged from 1.55 to 324.57 cc (median 20.22 cc). The mean dose to the target ranged from 44 to 60 Gy (median 53 Gy). Follow-up ranged from 6 to 71 months (median 30 months). Acute and chronic toxicity were assessed using Radiation Therapy Oncology Group (RTOG) morbidity criteria and tumor response was assessed by patient report, examination, and imaging. Overall survival, progression-free survival, and local control were calculated using the Kaplan-Meier method., Results: Cumulative 5-year local control, progression-free survival, and overall survival were 93%, 88%, and 89%, respectively. Two patients progressed after IMRT, one locally and one distantly. Each was treated with IMRT after multiple recurrences of benign meningioma over many years. Both were found to have malignant meningioma at the time of relapse after IMRT, and it is likely their tumors had already undergone malignant change by the time IMRT was given. Defined normal structures generally received a significantly lower dose than the target. The most common acute central nervous system (CNS) toxicity was mild headache, usually relieved with steroids. One patient experienced RTOG Grade 3 acute CNS toxicity, and 2 experienced Grade 3 or higher late CNS toxicity, with one possible treatment-related death. No toxicity was observed with mean doses to the optic nerve/chiasm up to 47 Gy and maximum doses up to 55 Gy., Conclusion: IMRT is a promising new technology that is safe and efficacious in the primary and adjuvant treatment of intracranial meningiomas. A history of local aggression may indicate malignant degeneration and predict a poorer outcome. Toxicity data are encouraging, but the potential for serious side effects exists, as demonstrated by one possible treatment-related death. Larger cohort and longer follow-up are needed to better define efficacy and late toxicity of IMRT.
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- 2002
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31. Clinical experience with intensity-modulated radiation therapy (IMRT) for prostate cancer with the use of rectal balloon for prostate immobilization.
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Teh BS, Woo SY, Mai WY, Mcgary JE, Carpenter LS, Lu HH, Chiu JK, Vlachaki MT, Grant WH 3rd, and Butler EB
- Subjects
- Aged, Aged, 80 and over, Humans, Male, Middle Aged, Prostatic Neoplasms diagnostic imaging, Tomography, X-Ray Computed, Catheterization, Immobilization, Prostatic Neoplasms radiotherapy, Radiotherapy Planning, Computer-Assisted, Radiotherapy, Conformal, Rectum diagnostic imaging
- Abstract
The implementation of intensity-modulated radiation therapy (IMRT) is the result of advances in imaging, radiotherapy planning technologies, and computer-controlled linear accelerators. IMRT allows both conformal treatment of tumors and conformal avoidance of the surrounding normal structures. The first patient treated with Peacock IMRT at Baylor College of Medicine took place in March 1994. To date, more than 1500 patients have been treated with IMRT; more than 700 patients were treated for prostate cancer. Our experience in treating prostate cancer with IMRT was reviewed. Patient and prostate motions are important issues to address in delivering IMRT. The Vac-Lok bag-and-box system, as well as rectal balloon for immobilization of patient and prostate gland, respectively, are employed. Treatment planning also plays a very important role. IMRT as a boost after conventional external beam radiotherapy is not our treatment strategy. To derive maximal benefits with this new technology, all patients received full course IMRT. Three separate groups of patients receiving (1) primary IMRT, (2) combined radioactive seed implant and IMRT, and (3) post-prostatectomy IMRT were addressed. Overall, toxicity profiles in these patients were very favorable. IMRT has the potential to improve treatment outcome with dose escalation while minimizing treatment-related toxicity.
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- 2002
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32. Intensity-modulated radiation therapy for pediatric medulloblastoma: early report on the reduction of ototoxicity.
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Huang E, Teh BS, Strother DR, Davis QG, Chiu JK, Lu HH, Carpenter LS, Mai WY, Chintagumpala MM, South M, Grant WH 3rd, Butler EB, and Woo SY
- Subjects
- Adolescent, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Audiometry, Cerebellar Neoplasms drug therapy, Child, Child, Preschool, Combined Modality Therapy, Female, Humans, Male, Medulloblastoma drug therapy, Radiation Tolerance, Radiotherapy Dosage, Retrospective Studies, Cerebellar Neoplasms radiotherapy, Hearing radiation effects, Medulloblastoma radiotherapy, Radiotherapy, Conformal methods
- Abstract
Purpose: The combination of cisplatin chemotherapy and radiation therapy for the treatment of medulloblastoma has been shown to cause significant ototoxicity, impairing a child's cognitive function and quality of life. Our purpose is to determine whether the new conformal technique of intensity-modulated radiation therapy (IMRT) can achieve lower rates of hearing loss by decreasing the radiation dose delivered to the cochlea and eighth cranial nerve (auditory apparatus)., Patients and Methods: Twenty-six pediatric patients treated for medulloblastoma were retrospectively divided into two groups that received either conventional radiotherapy (Conventional-RT Group) or IMRT (IMRT Group). One hundred thirteen pure-tone audiograms were evaluated retrospectively, and hearing function was graded on a scale of 0 to 4 according to the Pediatric Oncology Group's toxicity criteria. Statistical analysis comparing the rates of ototoxicity was performed using Fisher's exact test with two-tailed analysis., Results: When compared to conventional radiotherapy, IMRT delivered 68% of the radiation dose to the auditory apparatus (mean dose: 36.7 vs. 54.2 Gy). Audiometric evaluation showed that mean decibel hearing thresholds of the IMRT Group were lower at every frequency compared to those of the Conventional-RT Group, despite having higher cumulative doses of cisplatin. The overall incidence of ototoxicity was lower in the IMRT Group. Thirteen percent of the IMRT Group had Grade 3 or 4 hearing loss, compared to 64% of the Conventional-RT Group (p < 0.014)., Conclusion: The conformal technique of IMRT delivered much lower doses of radiation to the auditory apparatus, while still delivering full doses to the desired target volume. Our findings suggest that, despite higher doses of cisplatin, and despite radiotherapy before cisplatin therapy, treatment with IMRT can achieve a lower rate of hearing loss.
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- 2002
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33. Evaluation of patients after extraperitoneal lymph node dissection and subsequent radiotherapy for cervical cancer.
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Hasenburg A, Salama JK, Van TJ, Amosson C, Chiu JK, and Kieback DG
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- Adult, Combined Modality Therapy, Female, Humans, Hysterectomy, Lymph Node Excision methods, Lymph Nodes surgery, Middle Aged, Neoplasm Staging, Time Factors, Uterine Cervical Neoplasms drug therapy, Lymph Node Excision adverse effects, Lymph Nodes pathology, Uterine Cervical Neoplasms radiotherapy, Uterine Cervical Neoplasms surgery
- Abstract
Objective: The presence of nodal metastases is the most important prognostic factor in cervical cancer. To adjust our therapy based on the true extent of the patient's disease, we performed an extraperitoneal lymph node dissection (EPLND) in all patients with cervical cancer prior to radiotherapy (RT) or radical hysterectomy., Methods: Thirty-three patients with carcinoma of the cervix underwent EPLND. The value of this procedure as a diagnostic tool for monitoring the extension of the disease was determined. Additionally, EPLND/RT-associated treatment complications were monitored., Results: The combined treatment approach of EPLND with RT or chemotherapy/RT was without major complications. Nineteen patients showed a temperature elevation, but only one patient had a fever of greater than 39.0 degrees C. Fourteen (48.3%) of 29 patients experienced some degree of proctitis or diarrhea and 3 (10.3%) experienced cystitis during the course of RT. No grade 3 or 4 acute or late genitourinary or gastrointestinal toxicities were noted. EPLND changed the clinical management for 6 patients from a radical hysterectomy to RT and for 7 patients from standard-field RT to extended-field RT. Without EPLND these 7 patients would have received RT with standard pelvic fields that would not have treated involved lymph node areas at high risk for subsequent failure., Conclusion: Thirteen (44.8%) of 29 patients received a different treatment than would otherwise have been administered with standard treatment planning. Therefore, we suggest that EPLND should be performed in all patients with cervical cancer prior to radical surgery or RT., (©2002 Elsevier Science.)
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- 2002
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34. Intensity modulated radiotherapy (IMRT) decreases treatment-related morbidity and potentially enhances tumor control.
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Teh BS, Mai WY, Grant WH 3rd, Chiu JK, Lu HH, Carpenter LS, Woo SY, and Butler EB
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- Adolescent, Adult, Aged, Aged, 80 and over, Brain Neoplasms pathology, Child, Child, Preschool, Dose Fractionation, Radiation, Dose-Response Relationship, Radiation, Female, Head and Neck Neoplasms pathology, Humans, Infant, Male, Middle Aged, Morbidity, Prostatic Neoplasms pathology, Radiotherapy Dosage, Radiotherapy, Computer-Assisted, Radiotherapy, Conformal, Retrospective Studies, Brain Neoplasms radiotherapy, Head and Neck Neoplasms radiotherapy, Neoplasm Recurrence, Local radiotherapy, Prostatic Neoplasms radiotherapy, Radiation Oncology methods
- Abstract
Intensity modulated radiation therapy (IMRT), a new form of three-dimensional conformal radiation therapy (3DCRT), optimizes the concept of computer-controlled radiation deposition in tumor (target) while sparing adjacent normal structures. A retrospective review was done on the initial 185 patients with tumors in different sites including prostate cancer, head and neck cancer, pediatric tumors, adult brain tumors, and previously irradiated recurrent tumors treated with IMRT. Preliminary findings indicate that IMRT is a new clinically feasible tool in radiation oncology. Treatment-related morbidity profile was favorable. Tumor response, local control, and the ability to palliate previously irradiated patients are encouraging. Intensity modulated radiation therapy will allow dose escalation, leading to better tumor control.
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- 2002
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35. Gamma knife radiosurgery for treatment of trigeminal neuralgia in multiple sclerosis patients.
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Huang E, Teh BS, Zeck O, Woo SY, Lu HH, Chiu JK, Butler EB, Gormley WB, and Carpenter LS
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- Adult, Female, Follow-Up Studies, Humans, Male, Middle Aged, Multiple Sclerosis complications, Multiple Sclerosis pathology, Radiosurgery statistics & numerical data, Trigeminal Neuralgia complications, Trigeminal Neuralgia pathology, Multiple Sclerosis surgery, Radiosurgery instrumentation, Radiosurgery methods, Trigeminal Neuralgia surgery
- Abstract
Background: Trigeminal neuralgia is a paroxysmal pain syndrome commonly associated with multiple sclerosis. While gamma knife radiosurgery has been shown to be an effective treatment for most cases of trigeminal neuralgia, it is considered to be less efficacious in patients with multiple sclerosis and less viable as a treatment option., Methods: Seven patients with multiple-sclerosis-associated trigeminal neuralgia were identified from 50 consecutive patients treated for trigeminal neuralgia at the Memorial-Hermann Gamma Knife Radiosurgery Center. A Leksell gamma knife was used to deliver 80 or 90 Gy to a single 4-mm isocenter targeting the fifth nerve root entry zone into the pons. The patients were followed for a median period of 28 months and graded on a scale of 1 to 5, adopted from the Barrow Neurological Institute., Results: All 7 patients showed excellent responses to radiosurgery with complete resolution of their pain and cessation of pain medications. The time to maximal response varied from 1 day to 8 months after treatment. The only complication was persistent facial numbness over the distribution of V2 and V3 which occurred in 4 patients. One patient experienced a recurrence of pain (grade 3) 24 months after radiation treatment, and she is currently being treated with carbamazepine., Conclusions: Gamma knife radiosurgery is an effective treatment option for trigeminal neuralgia patients with multiple sclerosis. These patients should be informed that there appears to be a higher incidence of facial numbness and that a longer period of several months should be allowed before the full effects of treatment may be observed as compared to the general population., (Copyright 2002 S. Karger AG, Basel)
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- 2002
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36. Combining radiotherapy with gene therapy (from the bench to the bedside): a novel treatment strategy for prostate cancer.
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Teh BS, Aguilar-Cordova E, Vlachaki MT, Aguilar L, Mai WY, Caillouet J, Davis M, Miles B, Kadmon D, Ayala G, Lu HH, Chiu JK, Carpenter LS, Woo SY, Grant WH 3rd, Wheeler T, Thompson TC, and Butler EB
- Subjects
- Adenoviridae genetics, Animals, Antiviral Agents therapeutic use, CD4-Positive T-Lymphocytes metabolism, Combined Modality Therapy, Ganciclovir therapeutic use, Humans, Lung Neoplasms pathology, Lung Neoplasms secondary, Male, Mice, Mice, Inbred C57BL, Neoplasm Metastasis, Prostatic Neoplasms genetics, Prostatic Neoplasms pathology, Time Factors, Treatment Outcome, Tumor Cells, Cultured, Genetic Therapy methods, Prostatic Neoplasms therapy, Simplexvirus genetics
- Abstract
Combined radiotherapy and gene therapy is a novel therapeutic approach for prostate cancer. There are various potential benefits in combining ionizing radiation with gene therapy to achieve enhanced antitumor effects: A) ionizing radiation improves transfection/ transduction efficiency, transgene integration, and possibly, the "bystander effect" of gene therapy; B) gene therapy, on the other hand, may interfere with repair of radiation-induced DNA damage and increase DNA susceptibility to radiation damage in cancer cells, and C) radiotherapy and gene therapy target at different parts of the cell cycle. Preclinical data have demonstrated the enhanced antitumor effects of this combined approach in local tumor control, prolongation of survival, as well as systemic control. This combined radio-gene therapy is under study in an ongoing clinical trial in prostate cancer. Our study adds gene therapy to the standard of care therapy (radiotherapy). These treatment modalities have different toxicity profiles. The goal of this combined approach is to enhance cancer cure without an increase in treatment-related toxicity. This approach also offers a new paradigm in spatial cooperation, whereby two local therapies are combined to elicit both local and systemic effects. Early clinical results showed the safety of this approach.
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- 2002
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37. Important prognostic factors in patients with skull base erosion from nasopharyngeal carcinoma after radiotherapy.
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Lu TX, Mai WY, Teh BS, Hu YH, Lu HH, Chiu JK, Carpenter LS, Woo SY, and Butler EB
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- Adolescent, Adult, Aged, Analysis of Variance, Female, Follow-Up Studies, Humans, Male, Middle Aged, Nasopharyngeal Neoplasms mortality, Neoplasm Invasiveness, Neoplasm Recurrence, Local mortality, Neoplasm Staging, Prognosis, Proportional Hazards Models, Skull Base pathology, Skull Base Neoplasms mortality, Time Factors, Nasopharyngeal Neoplasms pathology, Nasopharyngeal Neoplasms radiotherapy, Skull Base Neoplasms pathology
- Abstract
Purpose: To evaluate the long-term outcome and prognostic factors in patients with skull base erosion from nasopharyngeal carcinoma after initial radiotherapy (RT)., Methods and Materials: From January 1985 to December 1986, 100 patients (71 males, 29 females) with a diagnosis of nasopharyngeal carcinoma were found on computed tomography (CT) to have skull base erosion. The mean age was 41 years (range 16-66). Ninety-six patients had World Health Organization type III undifferentiated carcinoma, and 4 had type I. The metastatic workup, including chest radiography, liver ultrasound scanning, and liver function test was negative. All patients underwent external beam RT (EBRT) alone to 66-80 Gy during 6-8 weeks. A daily fraction size of 2 Gy was delivered using 60Co or a linear accelerator. No patient received chemotherapy. All patients were followed at regular intervals after irradiation. The median follow-up was 22.3 months (range 2-174). Survival of the cohort was computed by the Kaplan-Meier method. The potential prognostic factors of survival were examined. Multivariate analyses were performed using the Cox regression model., Results: The 1, 2, 5, and 10-year overall survival rate for the cohort was 79%, 41%, 27%, and 13%, respectively. However, the subgroup of patients with both anterior cranial nerve (I-VIII) and posterior cranial nerve (IX-XII) involvement had a 5-year survival of only 7.7%. A difference in the time course of local recurrence and distant metastasis was observed. Both local recurrence and distant metastasis often occurred within the first 2 years after RT. However, local relapse continued to occur after 5 years. In contrast, no additional distant metastases were found after 5 years. The causes of death included local recurrence (n = 59), distant metastasis (n = 21), both local recurrence and distant metastasis (n = 1), and unrelated causes (n = 5). After multivariate analysis, complete recovery of cranial nerve involvement, cranial nerve palsy, and headache after irradiation were found to be independent prognostic factors in this cohort., Conclusions: We present one of the longest follow-ups of patients with nasopharyngeal carcinoma invading the skull base. Our results demonstrate the importance of cranial nerve involvement, recovery of headache, and cranial nerve palsy. These factors should be carefully evaluated from the history, physical examination, and imaging studies. A subgroup of patients with skull base involvement had long-term survival after RT alone. The findings of this study are important as a yardstick against which more aggressive strategies, such as combined radiochemotherapy and altered fractionation RT can be compared.
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- 2001
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38. Phase I/II trial evaluating combined radiotherapy and in situ gene therapy with or without hormonal therapy in the treatment of prostate cancer--a preliminary report.
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Teh BS, Aguilar-Cordova E, Kernen K, Chou CC, Shalev M, Vlachaki MT, Miles B, Kadmon D, Mai WY, Caillouet J, Davis M, Ayala G, Wheeler T, Brady J, Carpenter LS, Lu HH, Chiu JK, Woo SY, Thompson T, and Butler EB
- Subjects
- Adenoviridae, Adult, Aged, Aged, 80 and over, Combined Modality Therapy, Flutamide therapeutic use, Genetic Vectors therapeutic use, Humans, Leuprolide therapeutic use, Lymphatic Irradiation, Male, Middle Aged, Prostatic Neoplasms radiotherapy, Simplexvirus, Thymidine Kinase genetics, Genetic Therapy methods, Prostatic Neoplasms therapy
- Abstract
Purpose: To report the preliminary results of a Phase I/II study combining radiotherapy and in situ gene therapy (adenovirus/herpes simplex virus thymidine kinase gene/valacyclovir) with or without hormonal therapy in the treatment of prostate cancer., Methods and Materials: Arm A: low-risk patients (T1-T2a, Gleason score <7, pretreatment PSA <10) were treated with combined radio-gene therapy. A mean dose of 76 Gy was delivered to the prostate with intensity-modulated radiotherapy. Arm B: high-risk patients (T2b-T3, Gleason score >or=7, pretreatment PSA >or=10) were treated with combined radio-gene therapy and hormonal therapy. Hormonal therapy was comprised of a 4-month leuprolide injection and 2-week use of flutamide. Arm C: Stage D1 (positive pelvic lymph node) patients received the same regimen as Arm B, with the additional 45 Gy to the pelvic lymphatics. Treatment-related toxicity was assessed using Cancer Therapy Evaluation Program common toxicity score and Radiation Therapy Oncology Group (RTOG) toxicity score., Results: Thirty patients (13 in Arm A, 14 in Arm B, and 3 in Arm C) completed the trial. Median follow-up was 5.5 months. Eleven patients (37%) developed flu-like symptoms (Cancer Therapy Evaluation Program Grade 1) of fatigue and chills/rigors after gene therapy injection but recovered within 24 h. Four patients (13%) and 2 patients (7%) developed Grade 1 and 2 fever, respectively. There was no patient with weight loss. One patient in Arm B developed Grade 3 elevation in liver enzyme, whereas 11 and 2 patients developed Grade 1 and 2 abnormal liver function tests. There was no Grade 2 or above hematologic toxicity. Three patients had transient rise in creatinine. There was no RTOG Grade 3 or above lower gastrointestinal toxicity. Toxicity levels were as follows: 4 patients (13%), Grade 2; 6 patients (20%), Grade 1; and 20 patients (67%), no toxicity. There was 1 patient with RTOG Grade 3 genitourinary toxicity, 12 patients (40%) with Grade 2, 8 patients (27%) with Grade 1, and 9 patients (30%) with no toxicity. No patient dropped out from the trial or had to withhold treatment because of severe toxicity., Conclusions: This is the first trial of its kind in the field of prostate cancer that aims to expand the therapeutic index of radiotherapy by combining in situ gene therapy. Initial experience has demonstrated the safety of this approach. There is no added toxicity to each therapy used alone. Long-term follow-up and larger cohort studies are warranted to evaluate long-term toxicity and efficacy.
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- 2001
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39. The potential use of intensity modulated radiotherapy (IMRT) in women with pectus excavatum desiring breast-conserving therapy.
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Teh BS, Lu HH, Sobremonte S, Bellezza D, Chiu JK, Carpenter LS, Dennis WS, Woo SY, and Butler EB
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- Adult, Breast Neoplasms diagnostic imaging, Breast Neoplasms surgery, Carcinoma, Ductal, Breast diagnostic imaging, Carcinoma, Ductal, Breast surgery, Dose-Response Relationship, Radiation, Female, Humans, Mastectomy, Segmental, Radiotherapy Planning, Computer-Assisted, Time Factors, Tomography, X-Ray Computed, Breast Neoplasms radiotherapy, Carcinoma, Ductal, Breast radiotherapy, Funnel Chest complications, Radiotherapy, Conformal methods
- Abstract
The purpose of this study was to determine if intensity modulated radiation therapy (IMRT) offers a better treatment plan compared to conventional radiotherapy for patients with pectus excavatum desiring breast-conserving therapy and to assess the feasibility of simultaneous modulated accelerated radiation therapy (SMART) boost. A patient with pectus excavatum desired breast-conserving therapy for her early stage breast cancer. She underwent lumpectomy and axillary lymph node dissection followed by chemotherapy. She was then referred for radiotherapy. A breast board (Med-Tec) with aquaplast body cast was used to limit the movement of the patient, chest wall, and breasts before planning a computed tomography (CT) scan. IMRT including dose-volume histogram (DVH) was compared to that of the conventional plan using parallel opposed tangential beams with a 15-degree wedge pair. Forty-five gray was prescribed to the whole breast to each plan, while 50 Gy was prescribed to the tumor bed using IMRT with SMART boost in 25 fractions over 5 weeks. The coverage of the whole breast was adequate for both plans. IMRT allowed a more homogeneous dose distribution within the breast at the desired dose range. With IMRT there is less volume of ipsilateral lung receiving the radiation dose that is above the tolerance threshold of 15 Gy when compared to that of the conventional plan. However, there is more volume of surrounding normal tissues (the heart, spinal cord, and contralateral breast and lung) receiving low-dose irradiation when IMRT was employed. SMART boost was feasible, allowing a mean dose of 57 Gy to be delivered to the tumor bed simultaneously along with the rest of the breast in 5 weeks. IMRT is feasible in treating early breast cancer patients with pectus excavatum by decreasing the ipsilateral lung volume receiving high-dose radiation when compared to the conventional method. SMART boost shortens the overall treatment time that may have potential radiobiological benefit.
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- 2001
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40. Intensity-modulated radiation therapy (IMRT) for prostate cancer with the use of a rectal balloon for prostate immobilization: acute toxicity and dose-volume analysis.
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Teh BS, Mai WY, Uhl BM, Augspurger ME, Grant WH 3rd, Lu HH, Woo SY, Carpenter LS, Chiu JK, and Butler EB
- Subjects
- Aged, Aged, 80 and over, Digestive System radiation effects, Humans, Male, Middle Aged, Neoplasm Staging, Prostate diagnostic imaging, Prostatic Neoplasms diagnostic imaging, Prostatic Neoplasms pathology, Radiotherapy Dosage, Rectum diagnostic imaging, Tomography, X-Ray Computed, Urogenital System radiation effects, Catheterization methods, Immobilization, Prostatic Neoplasms radiotherapy, Radiotherapy, Conformal methods
- Abstract
Purpose: To report acute toxicity and to evaluate the relationship between dose-volume effects and acute toxicity in patients with localized prostate cancer, treated with intensity-modulated radiation therapy (IMRT)., Methods and Materials: Acute toxicity (both lower gastrointestinal [GI] and genito-urinary [GU]) in 100 patients treated with IMRT definitively to a prescribed dose of 70 Gy were assessed using RTOG scoring criteria. A rectal balloon was used for prostate immobilization. Mean doses to seminal vesicles, prostate, bladder, and rectum were recorded. Average irradiated bladder and rectal volumes above 65, 70, and 75 Gy were assessed. A relationship between dose volume and clinical toxicity was evaluated. All patients completed the full duration of acute toxicity assessment., Results: Mean doses to the prostate and seminal vesicles were 75.8 and 73.9 Gy. This represents a moderate dose escalation. Acute GI toxicity profile was very favorable. Eleven percent and 6% of the patients had grade 1 and 2 GI toxicity, respectively, while 83% had no GI complaint. For GU complaints, 38% and 35% had grade 1 and 2 toxicity, respectively, while 27% had no complaints. There was no grade 3 or higher acute GI or GU toxicity. Mean doses to the bladder were 22.8, 23.4, and 26.1 Gy for grade 0, 1, and 2 GU toxicity, respectively (p = 0.132). There is no statistically significant relationship between acute GU toxicity and the bladder volume receiving > 65 Gy, > 70 Gy, or > 75 Gy. In evaluating acute GI toxicity, there are very few grade 1 and 2 events. No relationship was found between acute rectal toxicity and mean rectal dose or irradiated rectal volumes receiving more than 65, 70, and 75 Gy., Conclusion: The findings are important with regard to the safety of IMRT, especially in reducing acute GI toxicity. Dose escalation with IMRT using a prostate immobilization technique is feasible. The findings are also important because they contribute to the clinical and dosimetric correlation aspect in the use of IMRT to treat prostate cancer. A larger cohort may be needed to determine if there is a relationship between acute GU toxicity and (a) mean bladder dose and (b) irradiated bladder volume receiving > 65 Gy, > 70 Gy, or > 75 Gy. A larger cohort of patients treated to a higher dose may be needed to show a relationship between dose volume and acute GI toxicity.
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- 2001
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41. Intensity modulated radiation therapy (IMRT) following prostatectomy: more favorable acute genitourinary toxicity profile compared to primary IMRT for prostate cancer.
- Author
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Teh BS, Mai WY, Augspurger ME, Uhl BM, McGary J, Dong L, Grant WH 3rd, Lu HH, Woo SY, Carpenter LS, Chiu JK, and Butler EB
- Subjects
- Aged, Aged, 80 and over, Combined Modality Therapy, Humans, Male, Middle Aged, Posture, Radiometry, Radiotherapy Dosage, Radiotherapy, Adjuvant, Rectum radiation effects, Salvage Therapy, Time Factors, Prostatectomy, Prostatic Neoplasms radiotherapy, Prostatic Neoplasms surgery, Radiotherapy, Conformal methods, Urinary Bladder radiation effects
- Abstract
Purpose: To report our initial experience on postprostatectomy IMRT (PPI), addressing acute genitourinary (GU) toxicity in comparison to primary IMRT (PI) for prostate cancer., Methods and Materials: From April 1998 to December 1999, 40 postprostatectomy patients were treated with intensity modulated radiation therapy (IMRT) to a median prescribed dose of 64 Gy (mean dose of 69 Gy). The Radiation Therapy Oncology Group (RTOG) scoring system was used to assess acute GU toxicity. Target volume and maximum and mean doses were evaluated. The mean doses to the bladder and irradiated bladder volume receiving >65 Gy were assessed. These were compared to those of 125 patients treated with PI to a prescribed dose of 70 Gy (mean dose of 76 Gy)., Results: The acute GU toxicity profile is more favorable in the PPI group with 82.5% of Grade 0-1 and 17.5% of Grade 2 toxicity compared to 59.2% and 40.8%, respectively, in the PI group (p < 0.001). There was no Grade 3 or higher toxicity in either group. The target volume was larger in the PPI group, while the maximum and mean doses to the target were higher in the PI group. The mean dose delivered to the bladder was higher in the PPI group. The irradiated bladder volume receiving >65 Gy was significantly larger in the PI group (p < 0.001)., Conclusions: PPI can be delivered with acceptable ute GU toxicity. The larger PPI target volume may be related to the difficulty in delineating prostatic fossa. Despite a larger target volume and a higher mean dose to the bladder, PPI produced a more favorable acute GU toxicity profile. This may be related to a combination of lower mean and maximum doses and smaller bladder volumes receiving >65 Gy in the PPI group, as well as urethral rather than bladder irradiation. The findings have implications in the evaluation of IMRT treatment plan for prostate cancer, whereby the irradiated bladder volumes above 65 Gy may be more meaningful than the mean dose to the bladder. Longer term toxicity results are awaited.
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- 2001
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42. Inhibition of restenosis with beta-emitting radiotherapy: Report of the Proliferation Reduction with Vascular Energy Trial (PREVENT).
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Raizner AE, Oesterle SN, Waksman R, Serruys PW, Colombo A, Lim YL, Yeung AC, van der Giessen WJ, Vandertie L, Chiu JK, White LR, Fitzgerald PJ, Kaluza GL, and Ali NM
- Subjects
- Angioplasty, Balloon, Coronary instrumentation, Aspirin therapeutic use, Automation, Beta Particles, Combined Modality Therapy, Coronary Angiography, Coronary Disease prevention & control, Coronary Disease radiotherapy, Coronary Vessels pathology, Coronary Vessels radiation effects, Dose-Response Relationship, Radiation, Drug Delivery Systems, Humans, Phosphorus Radioisotopes administration & dosage, Platelet Aggregation Inhibitors therapeutic use, Stents, Ticlopidine therapeutic use, Time Factors, Treatment Outcome, Coronary Disease therapy, Phosphorus Radioisotopes therapeutic use, Radiopharmaceuticals therapeutic use
- Abstract
Background: Intracoronary gamma- and beta-radiation have reduced restenosis in animal models. In the clinical setting, the effectiveness of beta-emitters has not been studied in a broad spectrum of patients, particularly those receiving stents., Methods and Results: A prospective, randomized, sham-controlled study of intracoronary radiotherapy with the beta-emitting (32)P source wire, using a centering catheter and automated source delivery unit, was conducted. A total of 105 patients with de novo (70%) or restenotic (30%) lesions who were treated by stenting (61%) or balloon angioplasty (39%) received 0 (control), 16, 20, or 24 Gy to a depth of 1 mm in the artery wall. Angiography at 6 months showed a target site late loss index of 11+/-36% in radiotherapy patients versus 55+/-30% in controls (P:<0.0001). A low late loss index was seen in stented and balloon-treated patients and was similar across the 16, 20, and 24 Gy radiotherapy groups. Restenosis (>/=50%) rates were significantly lower in radiotherapy patients at the target site (8% versus 39%; P:=0.012) and at target site plus adjacent segments (22% versus 50%; P:=0.018). Target lesion revascularization was needed in 5 radiotherapy patients (6%) and 6 controls (24%; P:<0.05). Stenosis adjacent to the target site and late thrombotic events reduced the overall clinical benefit of radiotherapy., Conclusions: beta-radiotherapy with a centered (32)P source is safe and highly effective in inhibiting restenosis at the target site after stent or balloon angioplasty. However, minimizing edge narrowing and late thrombotic events must be accomplished to maximize the clinical benefit of this modality.
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- 2000
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43. The use of intensity modulated radiotherapy for the treatment of extensive and recurrent juvenile angiofibroma.
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Kuppersmith RB, Teh BS, Donovan DT, Mai WY, Chiu JK, Woo SY, and Butler EB
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- Adult, Angiofibroma pathology, Child, Humans, Male, Nasopharyngeal Neoplasms radiotherapy, Neoplasm Invasiveness, Neoplasm Recurrence, Local radiotherapy, Nose Neoplasms radiotherapy, Radiotherapy Dosage, Radiotherapy, Conformal, Angiofibroma radiotherapy, Head and Neck Neoplasms radiotherapy
- Abstract
These case series are presented to describe the application and advantages of intensity modulated radiotherapy (IMRT) for the treatment of extensive and/or recurrent juvenile angiofibroma. Two patients were diagnosed with recurrence at 11 and 13 months postoperatively, and one was surgically unresectable. The affected areas included the base of skull, cavernous sinus, pterygopalatine fossa, infratemporal fossa, posterior orbit and nasopharynx. Highly conformal IMRT was delivered with limited radiation doses to the optic nerves, optic chiasm, brainstem, brain, spinal cord, lens, retina, mandible, and parotid. The total dose delivered to the tumor varied from 3400 to 4500 cGy. The tumor shrunk radiographically in all three cases and there was no endoscopic evidence of disease in two cases at 15 months and 40 months. There was no acute toxicity. Late toxicity was limited to one episode of epistaxis and persistent rhinitis in one patient. In conclusion, IMRT provides several advantages over conventional radiotherapy in the treatment of recurrent juvenile angiofibroma.
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- 2000
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44. Smart (simultaneous modulated accelerated radiation therapy) boost: a new accelerated fractionation schedule for the treatment of head and neck cancer with intensity modulated radiotherapy.
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Butler EB, Teh BS, Grant WH 3rd, Uhl BM, Kuppersmith RB, Chiu JK, Donovan DT, and Woo SY
- Subjects
- Aged, Feasibility Studies, Female, Humans, Immobilization, Male, Middle Aged, Radiation Injuries etiology, Radiotherapy, Conformal adverse effects, Time Factors, Carcinoma, Adenoid Cystic radiotherapy, Carcinoma, Squamous Cell radiotherapy, Dose Fractionation, Radiation, Head and Neck Neoplasms radiotherapy, Radiotherapy, Conformal methods
- Abstract
Purpose: To report the initial experience in the definitive treatment of head and neck carcinomas using SMART (Simultaneous Modulated Accelerated Radiation Therapy) boost technique. Radiation was delivered via IMRT (Intensity Modulated Radiotherapy). The following parameters were evaluated: acute toxicity, initial tumor response, clinical feasibility, dosimetry and cost., Methods and Materials: Between January 1996 and December 1997, 20 patients with primary head and neck carcinomas were treated with SMART boost technique. The treatment fields encompassed two simultaneous targets. The primary target included palpable and visible disease sites. The secondary target included regions at risk for microscopic disease. Daily fractions of 2.4 Gy and 2 Gy were prescribed and delivered to the primary and secondary targets to a total dose of 60 Gy and 50 Gy, respectively. Lower neck nodes were treated with a single conventional anterior portal. This fractionation schedule was completed in 5 weeks with 5 daily fractions weekly. Toxicity was evaluated by RTOG acute toxicity grading criteria, evidence of infection at immobilization screw sites, subjective salivary function, weight loss, and the need for treatment split. Mean follow-up was 15.2 months. Initial tumor response was assessed by clinical and radiographical examinations. Clinical feasibility was evaluated by the criteria: time to treat patient, immobilization, and treatment planning and QA time. In dosimetry, we evaluated the mean doses of both targets and normal tissues and percent targets' volume below goal. To evaluate cost, Medicare allowable charge for SMART boost was compared to those of conventional fractionated and accelerated radiotherapy., Results: ACUTE TOXICITY: None of the patients had a screw site infection and all patients healed well after completion of radiotherapy. Sixteen of 20 patients (80%) completed the treatment within 40 days without any split. Sixteen patients (80%) had RTOG Grade 3 mucositis while 10 patients (50%) had Grade 3 pharyngitis. Three of 20 patients (15%) had weight loss greater than 10% of their pretreatment weight. Ten patients (50%) required intravenous fluids, tube feeding or both. Nine patients (45%) reported moderate xerostomia with significant relief reported within 6 months. INITIAL TUMOR RESPONSE: 19 patients (95 %) had complete response (CR) while one had partial response (PR). The patient with PR had stable disease on imaging at 12 months follow-up. Two patients were found to have lung metastases at 2 months and 5 months follow-up. To date, there have been two local recurrences in the complete responders. Both patients had nasopharyngeal primary; one was retreated with radioactive Cesium-137 implant and the other died from the disease. CLINICAL FEASIBILITY: The average treatment time for a three-arc treatment was 17.5 minutes and 2.5 minutes for each additional arc. Eleven patients (55%) had four-arc treatment while six patients (30%) had five-arc treatment and three patients (15%) had three-arc treatment. Immobilization was reproducible within less than 2 mm. The treatment planning, QA and documentation prior to treatment averaged 2 days. DOSIMETRY: The mean doses to the primary and secondary targets were 64.4 Gy and 54.4 Gy, respectively; 8.9% of the primary target volume and 11.6% of the secondary target volume were below prescribed dose goal. The mean dose delivered to the mandible was 30 Gy, spinal cord 17 Gy, ipsilateral parotid 23 Gy, and contralateral parotid 21 Gy. COST: Total Medicare allowable charge for SMART boost was $7000 compared to $8600 (conventional) and $9400 (accelerated fractionation)., Conclusions: SMART boost technique is an accelerated radiotherapy scheme that can be delivered with acceptable toxicity. It allows parotid sparing as evidenced both clinically and by dosimetry. Initial tumor response has been encouraging. It is clinically feasible and cost saving. A larger population of patients and a long-term fol
- Published
- 1999
- Full Text
- View/download PDF
45. Intensity-modulated radiotherapy: first results with this new technology on neoplasms of the head and neck.
- Author
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Kuppersmith RB, Greco SC, Teh BS, Donovan DT, Grant W, Chiu JK, Cain RB, and Butler EB
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Child, Dose-Response Relationship, Radiation, Female, Humans, Male, Middle Aged, Radiotherapy methods, Retrospective Studies, Technology, Radiologic, Treatment Outcome, Head and Neck Neoplasms radiotherapy
- Abstract
Intensity-modulated beam radiotherapy (IMRT) delivers a highly conformal, three-dimensional (3-D) distribution of radiation doses that is not possible with conventional methods. When administered to patients with head and neck tumors, IMRT allows for the treatment of multiple targets with different doses, while simultaneously minimizing radiation to uninvolved critical structures such as the parotid glands, optic chiasm, and mandible. With 3-D computerized dose optimization, IMRT is a vast improvement over the customary trial-and-error method of treatment planning. We retrospectively reviewed the charts of the first 28 head and neck patients at our institution who were treated with IMRT. All had head and neck neoplasms, including squamous cell carcinoma, adenoid cystic carcinoma, paraganglioma, and angiofibroma. Total radiation doses ranged from 1,400 to 7,100 cGy, and daily doses ranged from 150 to 400 cGy/day. A quality assurance system ensured that computer-generated dosimetry matched film dosimetry in all cases. For midline tumors, this system allowed us to decrease the dose to the parotid glands to less than 3,000 cGy. The incidence of acute toxicity was drastically lower than that seen with conventional radiotherapy delivery to similar sites. This is the first report of the application of IMRT strictly to head and neck neoplasms. We discuss the indications, technique, and initial results of this promising new technology. We also introduce the concept of the Simultaneous Modulated Accelerated Radiation Therapy boost technique, which has several advantages over other altered fractionation schemes.
- Published
- 1999
46. Malignant meningioma: an indication for initial aggressive surgery and adjuvant radiotherapy.
- Author
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Dziuk TW, Woo S, Butler EB, Thornby J, Grossman R, Dennis WS, Lu H, Carpenter LS, and Chiu JK
- Subjects
- Adolescent, Adult, Aged, Child, Child, Preschool, Combined Modality Therapy, Female, Hemangiopericytoma radiotherapy, Hemangiopericytoma surgery, Humans, Male, Middle Aged, Multivariate Analysis, Neoplasm Recurrence, Local, Proportional Hazards Models, Retrospective Studies, Survival Analysis, Treatment Outcome, Meningeal Neoplasms radiotherapy, Meningeal Neoplasms surgery, Meningioma radiotherapy, Meningioma surgery
- Abstract
Malignant meningiomas constitute a rare subset of meningiomas and display a marked propensity for postsurgical recurrence. This retrospective study evaluates the various parameters which alter the recurrence rate. The records of all malignant meningioma patients treated from 1984 through 1992 were reviewed, and the time to recurrence or current patient status was determined, and the influence of various patient and disease parameters were analyzed. Thirty-eight patients were treated with 48 malignant meningioma resections performed (28 total and 20 subtotal), 25 at initial presentation and 23 for recurrent disease; 19 patients received postoperative radiotherapy. Subtypes included 32 anaplastic meningioma, 11 hemangiopericytoma, 2 meningiosarcoma, and 3 papillary meningioma. Followup ranged from 3 to 144 months, with five patients excluded from analysis. Actuarial disease free/progression free survival (DFS) at 5 years was 39% following total resection versus 0% after subtotal resection (p=0.001). For all totally excised lesions, the 5-yr DFS was improved from 28% for surgery alone to 57% with adjuvant radiotherapy (p=NS). Adjuvant irradiation following initial resection increased the 5-yr DFS rates from 15% to 80% (p=0.002). When administered for recurrent lesions, adjuvant radiotherapy improved the 2-yr DFS from 50% to 89% (p=0.015), but had no impact on 5-yr DFS. Multivariate analysis indicates extent of resection, adjuvant radiotherapy, and recurrence status are independent prognostic factors. Malignant meningiomas display a tendency for post surgical recurrence, with recurrence significantly increased for multicentric and recurrent disease. Complete surgical resection and the administration of adjuvant irradiation following initial resection are crucial to long-term control.
- Published
- 1998
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47. The Baylor College of Medicine experience with gold seed implantation.
- Author
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Butler EB, Scardino PT, Teh BS, Uhl BM, Guerriero WG, Carlton CE, Berner BM, Dennis WS, Carpenter LS, Lu HH, Chiu JK, Kent TS, and Woo SY
- Subjects
- Adult, Aged, Aged, 80 and over, Gold Radioisotopes administration & dosage, Humans, Male, Middle Aged, Neoplasm Recurrence, Local, Prostatic Neoplasms diagnostic imaging, Prostatic Neoplasms mortality, Radiotherapy Dosage, Radiotherapy, High-Energy, Retrospective Studies, Survival Rate, Ultrasonography, Brachytherapy, Gold Radioisotopes therapeutic use, Prostatic Neoplasms radiotherapy
- Abstract
Advances in imaging technology and implant technique have led to the resurgent interest and practice of brachytherapy for the treatment of prostate cancer. Brachytherapy is a form of radiation treatment in which radioactive sources are placed directly into the tumor; it offers the advantage of maximizing the radiation dose delivered to the tumor while sparing the adjacent normal tissue. Permanent implants have become an important component of radiation delivery. Interstitial gold radioisotope (Au-198) implants for prostate cancer were introduced at Baylor College of Medicine in 1965. The rationale for using Au-198, instead of the two most commonly used radioisotopes, Palladium-103 (Pd-103) and Iodine-125 (I-125), is discussed, and the Baylor implant technique is compared to that used in other centers. Retrospective review divides the patient population into pre-ultrasound versus post-ultrasound eras. Dosimetric calculation and disease control with the Au-198 seed implant for prostatic cancer are reviewed for the two different eras; toxicity is evaluated in the post-ultrasound era only. In the pre-ultrasound era, 510 patients were treated with pelvic lymph node sampling and gold seed insertion of the prostate followed by external beam radiation. In the post-ultrasound era, 54 patients were treated definitively with ultrasound-guided transperineal Au-198 implant followed by external beam irradiation. A small group of 30 patients in the post-ultrasound era were evaluated for the efficacy of Au-198 re-implantation for locally recurrent disease.
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- 1997
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48. Phase I-II study of combined 5-fluorouracil and cisplatin chemotherapy and altered fractionation radiotherapy for advanced squamous cell carcinoma of the cervix.
- Author
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Fishman A, Chiu JK, Girtanner RE, Dennis W, Carpenter LS, Lu HH, Woo SY, Kerley JM, and Kaplan AL
- Subjects
- Adult, Aged, Aged, 80 and over, Antimetabolites, Antineoplastic adverse effects, Antineoplastic Agents adverse effects, Antineoplastic Combined Chemotherapy Protocols adverse effects, Brachytherapy adverse effects, Carcinoma, Squamous Cell drug therapy, Carcinoma, Squamous Cell secondary, Cesium Radioisotopes adverse effects, Cesium Radioisotopes therapeutic use, Cisplatin adverse effects, Clinical Protocols, Combined Modality Therapy, Disease-Free Survival, Female, Fluorouracil adverse effects, Follow-Up Studies, Humans, Lymphatic Metastasis radiotherapy, Middle Aged, Prognosis, Radiopharmaceuticals adverse effects, Radiopharmaceuticals therapeutic use, Radiotherapy Dosage, Radium, Remission Induction, Treatment Outcome, Uterine Cervical Neoplasms drug therapy, Antimetabolites, Antineoplastic administration & dosage, Antineoplastic Agents administration & dosage, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Carcinoma, Squamous Cell radiotherapy, Cisplatin administration & dosage, Fluorouracil administration & dosage, Uterine Cervical Neoplasms radiotherapy
- Abstract
Forty patients with advanced carcinoma of the cervix were prospectively treated by an intermodality approach using chemotherapy combination concomitant with split-course hyperfractionated radiation therapy (RT). Cisplatin (CDDP) (60 mg/m2) was administered before radiotherapy initiation followed by 5-fluorouracil (5-FU) (750 mg/m2) for 5 days during the first week of irradiation. The same schedule was repeated in the last week of the RT, with 5-FU administration (1,000 mg/m2) for only 3 days. RT consisted of 5,020 cGy to the pelvis, followed by two intracavitary applications for a total of 5,000-5,500 mg/h radium equivalent when possible: 140 cGy/fraction was administered in the morning and evening, with a 6-h interval. The remainder of the external beam radiation was delivered at a standard daily fractionation of 180 cGy/fraction to a total dose of 5,020 cGy. This regimen of RT with concomitant chemotherapy had minimal toxicity and did not cause significant prolongation of the treatment program. However, a high rate of late complications was noted in patients who had extended-field RT due to paraaortic lymph node involvement. Thirty-two patients had complete response (CR) (80%). 24 (75%) of whom have no evidence disease (NED), with a median follow-up of 24 months. Our study suggests that this regimen of combined chemotherapy and RT in this group of patients with poor prognosis is effective and well tolerated, with acceptable acute toxicity and late morbidity.
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- 1997
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49. Characterization of hemolytic and cytotoxic Gallysins: a relationship with arylphorins.
- Author
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Beresford PJ, Basinski-Gray JM, Chiu JK, Chadwick JS, and Aston WP
- Subjects
- Amino Acid Sequence, Animals, Anti-Infective Agents chemistry, Anti-Infective Agents immunology, Anti-Infective Agents isolation & purification, Antibodies, Monoclonal chemistry, Antibodies, Monoclonal pharmacology, Biopolymers chemistry, Biopolymers immunology, Cell-Free System immunology, Glycoproteins immunology, Glycoproteins physiology, Hemolymph chemistry, Hemolymph drug effects, Hemolymph immunology, Hemolysin Proteins immunology, Hemolysin Proteins physiology, Hemolysis drug effects, Hemolysis immunology, Humans, Insect Proteins immunology, Insect Proteins isolation & purification, Insect Proteins physiology, Leukemia, Molecular Sequence Data, Moths, Rabbits, Structure-Activity Relationship, Tumor Cells, Cultured, Cytotoxicity, Immunologic, Glycoproteins chemistry, Hemolysin Proteins chemistry, Insect Proteins chemistry
- Abstract
Gallysin-1, an inducible effector protein in the protective response of Galleria mellonella larvae is a 75 kDa component of hemolytically active material (HAM) isolated from immune cell-free hemolymph. The sequence of the first 20 N-terminal amino acids of the antibacterial protein Gallysin-1 is identical to the predicted sequence of the first 20 amino acids of the Galleria arylphorin Lhp76 (larval hemolymph protein 76). A murine monoclonal antibody to the 20 amino acid N-terminal peptide of Gallysin-1 (GYPQYHYDVETRKLDPSLVN) provides additional evidence for a link between Gallysin-1 and Lhp76, and is used to characterize HAM further. HAM, initially characterized as a mixture of two proteins, Gallysin-1 and a 69 kDa component is now identified as a 450-500 kDa heteromultimer, designated Gallysin. In vivo levels of Gallysin rise during the effector phase of an induced immune response. The monoclonal antibody inhibits the hemolytic activity of Gallysin. In addition to a hemolytic activity for mammalian erythrocytes, Gallysin possesses a cytotoxic activity for the human tumor cell line, K562. Lipopolysaccharides (LPS) and a Pseudomonas aeruginosa vaccine induce a cytotoxic activity which reaches its maximum levels in the hemolymph early (2 hours post-vaccination) in the protective response. The partially purified cytotoxic material (Cyt-M) obtained from cell-free hemolymph collected 2 hours after vaccination has hemolytic activity and shows structural similarities to Gallysin and Lhp76. The previously established role of Gallysin-1 as an effector protein in the protective response of Galleria mellonella indicates that arylphorins may play a role in insect immune responses.
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- 1997
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50. Epiglottitis following preparation for allogeneic bone marrow transplantation.
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Murray JC, Chiu JK, Dorfman SR, and Ogden AK
- Subjects
- Acute Disease, Child, Combined Modality Therapy adverse effects, Epiglottis drug effects, Epiglottis radiation effects, Humans, Male, Precursor B-Cell Lymphoblastic Leukemia-Lymphoma therapy, Bone Marrow Transplantation, Cytarabine adverse effects, Epiglottitis etiology, Radiation Injuries etiology, Whole-Body Irradiation adverse effects
- Abstract
We describe a 7-year-old boy who developed acute, airway-threatening, non-infectious epiglottitis following high-dose cytosine arabinoside and total body irradiation preparative regimen for allogeneic BMT. Unlike gastrointestinal symptoms and oropharyngeal mucositis, acute epiglottitis is a previously unreported early complication following allogeneic BMT preparation. The pathogenesis of epiglottitis in our patient was presumably multifactorial, resulting from the combination of chemotherapy and irradiation. We recommend that this diagnosis be considered in the differential diagnosis of patients with significant upper airway symptoms following BMT preparation.
- Published
- 1995
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