42 results on '"Warkentin, H."'
Search Results
2. 18F-Fluorodeoxyglucose Positron Emission Tomography Parameters can Predict Long-Term Outcome Following Trimodality Treatment for Oesophageal Cancer
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Abraham, A.G., Riauka, T., Hudson, M., Ghosh, S., Zebak, S., Alba, V., Vaihenberg, E., Warkentin, H., Tankel, K., Severin, D., Bedard, E., Spratlin, J., Mulder, K., and Joseph, K.
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- 2023
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3. Skin Toxicity in Early Breast Cancer Patients Treated with Field-In-Field Breast Intensity-Modulated Radiotherapy versus Helical Inverse Breast Intensity-Modulated Radiotherapy: Results of a Phase III Randomised Controlled Trial
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Joseph, K., Vos, L.J., Gabos, Z., Pervez, N., Chafe, S., Tankel, K., Warkentin, H., Ghosh, S., Amanie, J., Powell, K., Polkosnik, L.-A., Horsman, S., MacKenzie, M., Sabri, S., Parliament, M.B., Mackey, J., and Abdulkarim, B.
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- 2021
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4. 18F-Fluorodeoxyglucose Positron Emission Tomography Parameters can Predict Long-Term Outcome Following Trimodality Treatment for Oesophageal Cancer
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Abraham, A.G., primary, Riauka, T., additional, Hudson, M., additional, Ghosh, S., additional, Zebak, S., additional, Alba, V., additional, Vaihenberg, E., additional, Warkentin, H., additional, Tankel, K., additional, Severin, D., additional, Bedard, E., additional, Spratlin, J., additional, Mulder, K., additional, and Joseph, K., additional
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- 2022
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5. PD-0501 Patterns of failure in anal cancer after IMRT and chemotherapy: Impact of 1 vs 2 doses of Mitomycin.
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Al Habsi, Z., primary, Joseph, K., additional, Abraham, A., additional, Al Balushi, M., additional, Tankel, G., additional, Mulder, K., additional, Warkentin, H., additional, Schiller, D., additional, Tankel, K., additional, Usmani, N., additional, Severin, D., additional, Paulson, K., additional, Karachiwala, H., additional, Wong, C., additional, Nijjar, T., additional, and Doll, C., additional
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- 2022
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6. PH-0331 Patterns And Predictors Of Relapse In Merkel Cell Carcinoma :Results From A Population Based Study.
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Joseph, K., primary, Wong, J., additional, Abraham, A., additional, Menon, A., additional, Ghosh, S., additional, Warkentin, H., additional, Walker, J., additional, and Salopek, T., additional
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- 2021
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7. SU‐F‐T‐249: Application of Human Factors Methods: Usability Testing in the Radiation Oncology Environment
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Warkentin, H, primary, Bubric, K, additional, Giovannetti, H, additional, Graham, G, additional, and Clay, C, additional
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- 2016
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8. Helical TomoTherapy in the Treatment of Anal Cancer: Treatment Planning and Acute Toxicity Data
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Loewen, S.K., primary, Joseph, K., additional, Syme, A., additional, Warkentin, H., additional, Field, C., additional, Tankel, K., additional, Polkosnik, L., additional, Usmani, N., additional, Severin, D., additional, and Nijjar, T., additional
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- 2011
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9. The Dosimetric Effect of Small Bowel Contrast on Rectal Cancer Patients for Conventional, Linac-based IMRT, and Helical Tomotherapy Plans
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Field, G., primary, Liu, D., additional, Joseph, K., additional, Dickey, M., additional, Polkosnik, L., additional, Warkentin, H., additional, and Severin, D., additional
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- 2011
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10. A Simple Technique for Scoring Radiotherapy Treatment Plans
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Field, G., primary, Warkentin, H., additional, Syme, A., additional, Powell, K., additional, Scrimger, R., additional, Parliament, M., additional, Jha, N., additional, and MacKenzie, M., additional
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- 2010
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11. Skin Sparing Helical Tomotherapy vs. 3D Conformal Radiotherapy: A Randomized Controlled Trial of Adjuvant Breast Radiotherapy-skin Dosimetry Substudy
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Capelle, L.R., primary, Warkentin, H., additional, Mackenzie, M., additional, Joseph, K., additional, Gabos, Z., additional, Tankel, K., additional, Chafe, S., additional, Pervez, N., additional, Ghosh, S., additional, and Abdulkarim, B., additional
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- 2010
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12. Comparison of RapidArc Volumetric Modulated Arc Therapy, Helical Tomotherapy, and 3D Conformal Radiotherapy for Pediatric Craniospinal Irradiation
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Patel, S., primary, Warkentin, H., additional, Powell, K., additional, Syme, A., additional, Warkentin, B., additional, and Fallone, G., additional
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- 2010
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13. A Prospective Dosimetric Analysis of Patterns of Failure in Head and Neck Cancer Patients Treated with Parotid Sparing Simultaneous Integrated Boost Intensity-modulated Radiotherapy (SIB-IMRT)
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Shakam, A., primary, Scrimger, R.A., additional, Liu, D., additional, Mohamed, M., additional, Parliament, M.B., additional, Field, C.G., additional, Cadman, P., additional, Warkentin, H., additional, Jha, N., additional, and El-Gayed, A., additional
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- 2009
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14. Assessing Cardiac Sparing in Breast Radiotherapy using MR and CT Breath-hold Imaging
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Menon, G.V., primary, Pervez, N., additional, Joseph, K., additional, Warkentin, H., additional, Yahya, A., additional, Wachowicz, K., additional, Al-Dhaibani, N., additional, Tankel, K., additional, Amanie, J., additional, and Fallone, G., additional
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- 2009
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15. 140 A PROSPECTIVE, MULTI-INSTITUTIONAL TRIAL OF IMRT IN HEAD AND NECK CANCER: CLINICAL OUTCOMES AND PATTERNS OF FAILURE
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Shakam, A., primary, Scrimger, R., additional, Mohamed, M., additional, Parliament, M., additional, Field, C., additional, El-Gayed, A., additional, Cadman, P., additional, Liu, D., additional, Jha, N., additional, Warkentin, H., additional, Skarsgard, D., additional, Gosh, S., additional, and Zhu, G., additional
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- 2009
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16. 78 COMBINED MR AND CT IMAGING FOR ASSESSING CARDIAC SPARING IN BREAST CANCER TREATMENTS
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Menon, G., primary, Pervez, N., additional, Joseph, K., additional, Warkentin, H., additional, Yahya, A., additional, Wachowicz, K., additional, Al-Dhaibani, N., additional, Tankel, K., additional, Amanie, J., additional, Gaetz, E., additional, and Fallone, G., additional
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- 2009
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17. 150 TOMOTHERAPY IN THE TREATMENT OF ANAL CANCER: ACUTE TOXICITY DATA
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Loewen, S., primary, Joseph, K., additional, Small, C., additional, Syme, A., additional, Warkentin, H., additional, Gaetz, E., additional, Tankel, K., additional, Severin, D., additional, Usmani, N., additional, Field, C., additional, and Nijjar, T., additional
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- 2009
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18. Po‐Thur Eve General‐06: Experimental Validation of the Eclipse AAA Algorithm
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Murray, B, primary, Newcomb, C, additional, Breitman, K, additional, Connors, S, additional, Dunscombe, P, additional, Field, G, additional, MacKenzie, M, additional, Rathee, S, additional, Robinson, D, additional, Warkentin, H, additional, and Fallone, B, additional
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- 2006
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19. Skin-sparing Helical Tomotherapy vs 3D-conformal Radiotherapy for Adjuvant Breast Radiotherapy: In Vivo Skin Dosimetry Study.
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Capelle L, Warkentin H, Mackenzie M, Joseph K, Gabos Z, Pervez N, Tankel K, Chafe S, Amanie J, Ghosh S, Parliament M, and Abdulkarim B
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- 2012
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20. Borderline personality disorder and sexuality: causes and consequences of dissociative symptoms.
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Mazinan RG, Dudek C, Warkentin H, Finkenstaedt M, Schröder J, Musil R, Kratzer L, Fuss J, and Biedermann SV
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Background: Sexual risk behavior in patients diagnosed with borderline personality disorder (BPD) is supposed to be associated with traumatic experiences and dissociative symptoms. Nevertheless, scientific research thereon is scarce which might be due to the high prevalence of sexual trauma and fear of overwhelming patients with explicit sexual content., Methods: We investigated a clinical sample of patients diagnosed with BPD (n = 114) and compared them to a sample of matched healthy controls (HC) (n = 114) concerning the dissociative symptoms derealization, depersonalization, and conversion in sexual situations. In a subgroup of patients with BPD (n = 41) and matched HC (n = 40) dissociative symptoms after exposure to an acoustically presented erotic narrative were assessed in the lab. Regression analyses were used to examine the associations between sexual trauma, post-traumatic stress disorder (PTSD), dissociation in sexual situations, and risky sexual behavior., Results: Patients diagnosed with BPD endorsed higher dissociative symptoms in sexual situations retrospectively and in the lab compared to HC. Regression analyses revealed that depersonalization and conversion symptoms in sexual situations were explained by severity of BPD, while derealization was explained by PTSD symptomatology. Impulsive and sexual behavior with an uncommitted partner were higher in the BPD group and explained by derealization, while conversion showed an inverse association., Conclusion: Our findings highlight the importance of addressing distinct dissociative symptoms in sexual situations when counselling and treating women with BPD. In the long term, this could contribute to a reduction in sexual risk behavior in patients with BPD., Trial Registration: This analysis is part of a larger ongoing study and was registered prior to accessing the data (Registration trial DRKS00029716)., (© 2024. The Author(s).)
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- 2024
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21. Early Warning for the Electrolyzer: Monitoring CO 2 Reduction via In-Line Electrochemical Impedance Spectroscopy.
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Warkentin H, O'Brien CP, Holowka S, Maxwell B, Awara M, Bouman M, Zeraati AS, Nicholas R, Ip AH, Elsahwi ES, Gabardo CM, and Sinton D
- Abstract
The electrochemical CO
2 reduction reaction (CO2 RR) to fuels and feedstocks presents an opportunity to decarbonize the chemical industry, and current electrolyzer performance levels approach commercial viability. However, stability remains below that required, in part because of the challenge of probing these electrolyzer systems in real time and the challenge of determining the root cause of failure. Failure can result from initial conditions (e. g., the over- or under-compression of the electrolyzer), gradual degradation of components (e. g., cathode or anode catalysts), the accumulation of products or by-products, or immediate changes such as the development of a hole in the membrane or a short circuit. Identifying and mitigating these assembly-related, gradual, and immediate failure modes would increase both electrolyzer lifetime and economic viability of CO2 RR. We demonstrate the continuous monitoring of CO2 RR electrolyzers during operation via non-disruptive, real-time electrochemical impedance spectroscopy (EIS) analysis. Using this technique, we characterise common failure modes - compression, salt formation, and membrane short circuits - and identify electrochemical parameter signatures for each. We further propose a framework to identify, predict, and prevent failures in CO2 RR electrolyzers. This framework allowed for the prediction of anode degradation ~11 hours before other indicators such as selectivity or voltage., (© 2023 CERT Systems Inc and The Authors. ChemSusChem published by Wiley-VCH GmbH.)- Published
- 2023
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22. Design and Implementation of a Multidisciplinary High-Fidelity Simulation Course for the Management of Malignant Spinal Cord Compression.
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Zhu YM, Chwyl B, Fawcett S, Yang F, Warkentin H, Ghosh S, Debenham B, Duimering A, and Al Balushi M
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- Humans, Pilot Projects, Learning, Allied Health Personnel, High Fidelity Simulation Training, Spinal Cord Compression etiology, Spinal Cord Compression therapy
- Abstract
High-fidelity simulation (HFS) training is suited to high-stakes, uncommon situations such as malignant spinal cord compression (MSCC), allowing for rare hands-on practice. This pilot study was created as the first of its kind to examine educational outcomes of a radiation therapist (RTT)-led multidisciplinary radiation oncology (RO) emergency simulation course. A multidisciplinary course design team composed of RO residents, radiation oncologists, RTT course instructors, and medical physicists created a high-fidelity MSCC simulation course using collaboratively developed learning goals. Fifteen learners including RO residents, senior RTT students, and a medical physics (MP) resident participated in a live, RTT-facilitated simulation. Participants completed anonymized pre- and post-simulation standard interdisciplinary education perception (IEP) scales and a course evaluation assessing educational outcomes. Standard IEP questionnaire results showed highly favorable perceptions of respondents' own specialty and other allied specialties, with mean total pre-simulation scores of 91.76 and post-simulation scores of 94.23. The course evaluation assessed 10 learning objective domains, with significant improvements seen in self-rated post-course knowledge in 9 domains. Pre-course evaluations showed that 6/15 participants agreed or strongly agreed that they felt comfortable in their knowledge of all included domains; after course completion, 14/15 participants agreed or strongly agreed they felt comfortable in all domains. Collaboratively designed and led HFS courses are not only viable but can be an effective means of improving learning outcomes for RO residents, RTT students, and MP residents., (© 2023. The Author(s) under exclusive licence to American Association for Cancer Education.)
- Published
- 2023
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23. Long-Term Patient-Reported Quality of Life of Anal Cancer Survivors Treated With Intensity Modulated Radiation Therapy and Concurrent Chemotherapy: Results From a Prospective Phase II Trial.
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Joseph K, Balushi MA, Ghosh S, Stenson T, Abraham A, Elangovan A, Warkentin H, Paulson K, Tankel K, Usmani N, Severin D, Schiller D, Wong C, Mulder K, Doll C, King K, and Nijjar T
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- Female, Humans, Quality of Life, Diarrhea etiology, Patient Reported Outcome Measures, Radiotherapy, Intensity-Modulated adverse effects, Radiotherapy, Intensity-Modulated methods, Cancer Survivors, Fecal Incontinence etiology, Anus Neoplasms therapy
- Abstract
Purpose: Intensity modulated radiation therapy (IMRT) has confirmed its superiority in improving acute treatment-related toxicities in anal cancer, without compromising tumor control. However, the effect of IMRT on long-term quality of life (QOL) is poorly documented. The study prospectively evaluated the long-term patient-reported QOL after IMRT-based chemoradiation in anal cancer., Methods and Materials: Fifty-eight patients treated with IMRT and concurrent 5 fluorouracil/mitomycin-C were enrolled in the study. A prespecified secondary endpoint was prospective evaluation of long-term QOL. Fifty-four patients underwent QOL evaluation at baseline, after treatment, and during follow-up until 60 months, with European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-C30 (EORTC QLQ-C30) scales and the Colorectal Cancer-Specific Quality Of Life Questionnaire (QLQ-CR29) scales. The QOL scores at baseline and posttreatment periods were compared., Results: For QLQ-C30, at 60 months, the mean scores of global health status, all functional scales, and all symptoms except diarrhea had improved, indicating normalization of QOL. Clinically and statistically significant improvements in the global health status (15.4; P = .003), role functioning (19.3; P = .0017), emotional functioning (18.9; P = .008), and social functioning (29.8; P ≤ .001) were observed. Diarrhea persisted as a concern over the years (P = .172). For European Organization for Research and Treatment of Cancer QLQ-CR29, rectal pain (-38.6; P = .001), mucous or blood discharge per rectum (-22.8; P = .005), and perianal soreness (-37.3; P ≤ .001) were improved both clinically and statistically. Clinically significant fecal leakage was reported by 16% of patients (5.6; P = .421). Volumes receiving 45 and 54 Gy were independent predictors for fecal incontinence. Clinically and statistically significant urinary incontinence occurred in 21% of patients (17.5; P = .014). Deterioration of dyspareunia was clinically significant (26.7; P = .099) at 60 months., Conclusions: Compared with historical data, IMRT is associated with reduced long-term effects on QOL. The majority of patients treated with IMRT experienced clinically significant recovery of function and improvement in QOL over 5 years after completion of treatment. Specific toxicities such as chronic diarrhea, fecal incontinence, and urinary and sexual dysfunction were primarily responsible for deterioration of the long-term QOL. Future research aimed at reducing such toxicities is needed to further improve long-term QOL in anal cancer., (Copyright © 2023 Elsevier Inc. All rights reserved.)
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- 2023
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24. Use of the CytoSorb® filter for elimination of residual therapeutic argatroban concentrations during heparinized cardiopulmonary bypass for heart transplantation.
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Koster A, Warkentin H, von Dossow V, and Morshuis M
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- Humans, Adult, Cardiopulmonary Bypass, Heparin therapeutic use, Arginine, Anticoagulants therapeutic use, Heart Transplantation
- Abstract
Introduction: No antidote or established extracorporeal elimination strategy is available for argatroban. Hemadsorption facilitates elimination of smaller drugs., Case Report: A 34-year-old patient underwent urgent heart transplantation. Because of a history of heparin-induced thrombocytopenia, preoperative anticoagulation was performed with argatroban. Despite ceasing of the continuous infusion of argatroban 2 h before surgery, concentration only declined from 0.60 μg/ml to 0.58 μg/ml before surgery, and the activated clotting time (ACT) value shortly was 223 s. Microvascular bleeding had been observed when starting surgery. A CytoSorb® absorption column was integrated into the system of the heparin-anticoagulated cardiopulmonary bypass (CPB) circuit and a flow of 400 mL/min provided during the 2 h of extracorporeal circulation. The argatroban concentration after weaning from CPB was 0.04 μg/ml and satisfying hemostasis had been achieved after protamine administration., Conclusion: Data indicate that the CytoSorb® absorption column might be an effective tool for quick extracorporeal removal of therapeutic concentrations of argatroban.
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- 2023
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25. Families with Mentally Ill Parents and Their Partners: Overlaps in Psychiatric Symptoms and Symptom Coping.
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Wiegand-Grefe S, Warkentin H, Adema B, Daubmann A, Kilian R, Winter SM, Lambert M, Wegscheider K, and Busmann M
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- Child, Humans, Adaptation, Psychological, Spouses psychology, Mentally Ill Persons, Mental Disorders epidemiology, Mental Disorders psychology, Psychotic Disorders
- Abstract
Partners in families with a mentally ill parent often experience psychiatric symptoms themselves. Recent studies indicate that there might be overlaps in disorder-specific symptom areas between partners and spouses. This study aimed at examining associations in psychiatric symptoms and symptom coping in partners in families with a mentally ill parent, e.g., having a psychiatric diagnosis according to the International Classification of Diseases (ICD-10). Furthermore, a moderation of the psychiatric symptoms of the parent with a mental illness on the association in symptom coping was assumed. Families with at least one parent with a mental illness were recruited into the longitudinal "Children of Mentally Ill Parents" (CHIMPS) trial at seven clinical centers in Germany and Switzerland. In total, 139 families were included in the current study. Psychiatric symptoms were assessed using the Brief Symptom Inventory (BSI), Clinical Global Impression scale (CGI), Global Assessment of Functioning (GAF), and Patient Health Questionnaire (PHQ), while symptom coping strategies were measured using the Freiburger Fragebogen zur Krankheitsverarbeitung (FKV). Regression analyses have indicated an association in psychiatric symptoms between mentally ill parents and their partners concerning psychosocial functioning, somatic, and stress-related symptoms. Additionally, one symptom coping strategy of the partners was predicted by the same strategy of the parent with a mental illness. The results emphasize the importance of screening and providing support to parents burdened by the mental disorder of their partners, especially regarding the children in these partnerships.
- Published
- 2023
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26. Is Radiation-Induced Cardiac Toxicity Reversible? Prospective Evaluation of Patients With Breast Cancer Enrolled in a Phase 3 Randomized Controlled Trial.
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Abraham A, Sanghera KP, Gheisari F, Koumna S, Riauka T, Ghosh S, Warkentin H, Gabos Z, Chafe S, Tankel K, Huang F, Sabri S, Paterson DI, Abdulkarim B, and Joseph K
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- Cardiotoxicity, Female, Heart diagnostic imaging, Humans, Prospective Studies, Breast Neoplasms radiotherapy, Radiation Injuries prevention & control
- Abstract
Purpose: Myocardial perfusion defects after breast radiation therapy (RT) correlate with volume of irradiated left ventricle (LV). We aimed to determine the relationship between myocardial perfusion, LV dosimetry, and grade ≥2 late cardiac events in patients with breast cancer undergoing adjuvant RT., Methods and Materials: A randomized study evaluated the benefit of inverse-planned intensity modulated radiation therapy over forward-planned intensity modulated radiation therapy for radiation toxicity in breast cancer. A secondary endpoint was evaluating cardiac perfusion by single-photon emission computed tomography done at baseline, 6 months, 1 year, 2 years, and 5 years post-RT. We used receiver operating curve and regression analysis to identify association between perfusion, radiation dose-volumes, and the risk of late cardiac events., Results: Of 181 patients who received adjuvant RT, 102 were patients with cancer in the left breast (called in this study the left-sided group) and 79 were patients with cancer in the right breast (called in this study the right-sided group). Median follow-up was 127 months (range, 19-160 months). A significant worsening of perfusion defects occurred after RT in the left-sided group, which improved by 1 year. Late cardiac events were found among 16 patients (17.2%) in the left-sided group and 4 patients (5.5%) in the right-sided group. Perfusion changes did not correlate with late cardiac events, but LV dose-volumes correlated with late cardiac events. Maintaining the LV volume receiving 5 Gy and 10 Gy to <42 cc and <38cc, respectively, can reduce the risk of radiation-related late cardiac events at 10 years to <5% over baseline., Conclusions: RT was associated with short-term perfusion defects that improved within 1 year and was not correlated with late cardiac events. The ventricular volumes receiving 5 Gy and 10 Gy were correlated with late cardiac events., (Copyright © 2022 Elsevier Inc. All rights reserved.)
- Published
- 2022
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27. Patterns and predictors of relapse in Merkel cell carcinoma: Results from a population-based study.
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Joseph K, Wong J, Abraham A, Zebak J, Patel A, Jones Thachuthara A, Iqbal U, Pham TM, Menon A, Ghosh S, Warkentin H, Walker J, Jha N, Faruqi S, Salopek TG, and Smylie M
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- Aged, Humans, Neoplasm Recurrence, Local pathology, Neoplasm Staging, Prospective Studies, Radiotherapy, Adjuvant, Retrospective Studies, Sentinel Lymph Node Biopsy, Carcinoma, Merkel Cell radiotherapy, Carcinoma, Merkel Cell surgery, Skin Neoplasms pathology
- Abstract
Background and Purpose: Prospective data evaluating the role of adjuvant radiotherapy (RT) for Merkel Cell Carcinoma(MCC) is lacking. To better understand the efficacy of adjuvant RT, a population-based patterns of failure study was conducted., Methods: We identified MCC patients treated from 1988 to 2018.Primary outcome measures were recurrence-free survival (RFS), overall survival (OS) and MCC-specific survival (MCC-SS). Charlson Co-morbidity Index (CCI) was also calculated., Results: 217 patients with mean age 79 (range: 33-96) were analyzed. The median follow-up was 40 months. Treatments were: surgery(S) alone (n = 101, 45%) or S + RT(n = 116, 55%).Local recurrence (LR) was low in stage I (n = 6, 6.5%) with clear margin of ≥1 cm, negative sentinel lymph node biopsy (SLNB) without high-risk factors, irrespective of adjuvant RT. Tumor size ≥ 2 cm (HR:2.95; p = 0.024) and immunosuppression(HR:3.98; p = 0.001) were associated with high risk of nodal failure. Adjuvant RT was associated with significant reduction in regional failure (HR:0.36; p = 0.002). Distant metastases (DM) were infrequent in stage I (4/90) and stage II (4/34), compared to stage III (32/93). Adjuvant RT improvedRFS but did not influence MCC-SS and OS. CCI was a significant predictor of OS., Conclusions: Adjuvant RT improvedRFS, withoutimpact on MCC-SS and OS. Co-morbidity rather than RT influenced OS. Adjuvant RT may be avoided instage I patients with negative SLNB and no associated high-risk factors. Prophylactic RNI could be considered in stage II with high risk features, inspite of negative SLNB. Stage III patients benefited from adjuvant RNI, but no impact on prevention of DM., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2022
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28. Concomitant Use of Proton Pump Inhibitors With Capecitabine Based Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer: Is it Safe?
- Author
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Menon A, Abraham AG, Mahfouz M, Thachuthara JJ, Usmani N, Warkentin H, Ghosh S, Nijjar T, Severin D, Tankel K, Paulson K, Mulder K, Roa W, and Joseph K
- Subjects
- Adult, Aged, Aged, 80 and over, Antineoplastic Combined Chemotherapy Protocols adverse effects, Capecitabine administration & dosage, Chemoradiotherapy adverse effects, Female, Fluorouracil administration & dosage, Humans, Male, Middle Aged, Neoadjuvant Therapy methods, Neoplasm Recurrence, Local pathology, Proton Pump Inhibitors administration & dosage, Rectal Neoplasms mortality, Rectal Neoplasms pathology, Retrospective Studies, Treatment Outcome, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Chemoradiotherapy methods, Proton Pump Inhibitors therapeutic use, Rectal Neoplasms therapy
- Abstract
Aim: Capecitabine (Cape) is routinely used for the neoadjuvant chemoradiation treatment (NACRT) of locally advanced rectal cancers (LARCs). Previous reports have suggested that the concomitant use of proton pump inhibitors (PPIs) may affect the efficacy of Cape, although the true effect of PPIs when used with Cape as a radiosensitizer for neoadjuvant radiation is unclear. The aim of our study was to evaluate the impact of concurrent PPI use along with fluorouracil (FU) and Cape based NACRT in terms of pathologic and oncological outcomes, in patients with LARC., Methods: LARC patients treated at our center with NACRT from 2010 to 2016 were identified. Postoperative pathology and follow-up outcomes were examined for any differences with relation to the use of PPIs concurrently with FU and Cape based NACRT and adjuvant chemotherapy regimens., Results: Three hundred four and 204 patients received treatment with FU and Cape based NACRT. No difference in pathologic complete response rate was noted between the 2 arms with the concurrent use of PPIs (25.8% and 25%, respectively, P=0.633); or with and without the use of PPIs in the Cape-NACRT arm specifically (20% and 20.7%, P=0.945). At a median follow-up of 5 years, no statistical difference in local or distant control was noted in the Cape-NACRT patients, with and without concomitant PPI use (P=0.411 and 0.264, respectively).Multivariate analysis showed no association of PPI use and NACRT with Cape, in terms of local control (hazard ratio=0.001, P=0.988) or overall survival (hazard ratio=1.179, confidence interval=0.249-5.579, P=0.835)., Conclusions: Our study revealed that there was no adverse pathologic or oncological outcome with the concurrent use of PPIs along with Cape-NACRT in the treatment of LARC. We report that it may be safe to use PPIs if essential, in this clinical setting, although it would be wise to exercise caution., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)
- Published
- 2021
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29. Prognostic utility of pre- and post-treatment FDG-PET parameters in anal squamous cell carcinoma.
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Duimering A, Riauka T, Nijjar Y, Ghosh S, MacEwan R, Warkentin H, Schiller D, Tankel K, Usmani N, Severin D, Nijjar T, Fairchild A, Mulder K, Doll C, Wong C, and Joseph K
- Subjects
- Adult, Aged, Anus Neoplasms drug therapy, Anus Neoplasms radiotherapy, Carcinoma, Squamous Cell drug therapy, Carcinoma, Squamous Cell radiotherapy, Chemoradiotherapy, Disease Progression, Female, Fluorodeoxyglucose F18, Humans, Male, Middle Aged, Multivariate Analysis, Neoplasm Recurrence, Local diagnostic imaging, Positron-Emission Tomography methods, Prognosis, Radiopharmaceuticals, Retrospective Studies, Tumor Burden, Anus Neoplasms diagnostic imaging, Carcinoma, Squamous Cell diagnostic imaging
- Abstract
Background and Purpose: We prospectively assessed the contributions of PET to initial staging, early detection of treatment failures, and prognostication in patients with anal squamous cell carcinoma (ASCC)., Materials and Methods: Consecutive patients with ASCC referred for radical chemoradiotherapy (CRT) consented to undergo FDG-PET imaging pre-treatment and at 3 and 6 months post-treatment. Clinicopathologic data were collected and CT and PET imaging reviewed for contribution to staging and recurrence detection. Maximum standardized uptake value (SUVmax), peak standardized uptake value (SUVpeak), metabolic tumour volume (MTV), and total lesion glycolysis (TLG) were assessed for association with progression-free survival (PFS), cause-specific survival (CSS), and overall survival (OS) using the Kaplan-Meier and Cox regression models., Results: Between 2009 and 2016, 73 patients with clinical stages I-IIIB ASCC completed curative-intent CRT. Median follow-up was 48 months. 14 patients died and 18 patients experienced disease progression. 4-year PFS, CSS, and OS were 73%, 87%, and 84%, respectively. A pre-treatment MTV >35 cm
3 predicted for worse PFS (p = 0.011) and CSS (p = 0.024) on univariate and multivariate analyses, employing an MTV definition of voxels ≥25% of SUVmax. Higher 6-month post-treatment SUVmax and SUVpeak predicted for worse PFS and OS (p ≤ 0.011). Pre-treatment SUVmax, SUVpeak, and TLG, and 3-month post-treatment SUVmax and SUVpeak did not significantly correlate with survival outcomes., Conclusions: Our findings support that pre-treatment MTV provides meaningful prognostic information, with suggestion that an MTV delineation threshold of voxels ≥25% of SUVmax is appropriate in the anal region. Post treatment, the combination of clinical examination and PET effectively detected all treatment failures. Higher 6-month post-treatment SUVmax and SUVpeak predicted worse PFS and OS; however, the optimal timing of post-treatment PET imaging remains unclear., (Copyright © 2019 Elsevier B.V. All rights reserved.)- Published
- 2019
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30. Cetuximab-radiotherapy combination in the management of locally advanced cutaneous squamous cell carcinoma.
- Author
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Joseph K, Alkaabi K, Warkentin H, Ghosh S, Jha N, Smylie M, and Walker J
- Subjects
- Aged, Aged, 80 and over, Carcinoma, Squamous Cell pathology, Combined Modality Therapy, Female, Humans, Male, Middle Aged, Neoplasm Staging, Skin Neoplasms pathology, Treatment Outcome, Antineoplastic Agents, Immunological therapeutic use, Carcinoma, Squamous Cell drug therapy, Carcinoma, Squamous Cell radiotherapy, Cetuximab therapeutic use, Skin Neoplasms drug therapy, Skin Neoplasms radiotherapy
- Abstract
Introduction: We report the outcomes of using a combination of cetuximab with radiation therapy (Cetux-RT) to treat a selected group of patients with locally advanced (unresectable) cutaneous squamous cell carcinoma (LA-cSCC). This study presents two-year efficacy and safety data for 8 patients with LA-cSCC treated within a single institution., Methods: Between 2014 and 2017 a total of eight patients (seven males, one female) with LA-cSCC received curative intent treatment with Cetux-RT. All patients received an initial loading dose of cetuximab at 400 mg/m
2 seven days prior to radiotherapy, followed by weekly treatment with 250 mg/m2 , continuing through the end of radiotherapy. Radiation doses were 6600 cGy/30 fr (n = 2), 6300 cGy/30fr (n = 2) and 5500 cGy/22 fr (n = 4)., Results: The median age was 81 years (range, 55-87). The ECOG performance status of all patients was between 0 and 2. With a median duration of follow-up of 25 months (range 10-48 months), five patients remain in a complete response. After a partial response, another patient has relapsed and is receiving palliative chemotherapy, while two patients have died during the period of follow up (one of whom died following progression of disease, the other of an unrelated cause). Treatment in this group of patients was well tolerated, with most toxicities ≤ grade 2, and no toxicities of grade 4/5 reported., Conclusions: Cetux-RT was well tolerated and provided durable disease control within this patient sample. Our data support the use of the Cetux-RT regimen for selected patients with inoperable LA-cSCC and adequate performance status., (© 2018 The Royal Australian and New Zealand College of Radiologists.)- Published
- 2019
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31. Peri-anal surface dose in anal canal VMAT radiotherapy.
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Joseph K, Rose B, Warkentin H, Yun J, Ghosh S, and Tankel K
- Subjects
- Aged, Aged, 80 and over, Algorithms, Female, Humans, Male, Middle Aged, Radiotherapy Dosage, Radiotherapy Planning, Computer-Assisted methods, Thermoluminescent Dosimetry, Anal Canal radiation effects, Anus Neoplasms radiotherapy
- Abstract
Introduction: Skin bolus may routinely be used in the perineum to build up the surface dose in the treatment of anal cancer (ACC); this may contribute to significant acute skin toxicity. Skin bolus may not be needed with the introduction of modern radiotherapy techniques if these planning techniques would achieve adequate surface dose. Our study is to ascertain if appropriate skin dose can be achieved without the use of bolus when VMAT is used in the treatment of ACC., Methods: The study includes 10 ACC patients treated with VMAT radiotherapy. Optically stimulated luminescence dosimeters (OSLD) are used to evaluate whether the calculated dose for the VMAT planning technique (VMAT-PT) accurately predicted the dose delivered to peri-anal target region without bolus. The OSLD recorded the dose at the anal verge or at the lower most extent of the tumour for each patient over two fractions. The OSLD was read after each of the two fractions, and the average value was reported. The mean dose over a volume centred on the anal marker was calculated in the treatment planning system (TPS)., Results: The mean TPS-calculated dose was 186.1 cGy. The mean of the OSLD-measured doses was 205.7 cGy for a single fraction. The mean of the measured doses was 10.6% higher than the mean of the calculated doses., Conclusions: The calculated dose for the VMAT-PT consistently under-predicted the dose delivered to the peri-anal target region without bolus. Routine use of skin bolus could be avoided with VMAT-PT when the patient is treated in a supine position., (© 2018 The Royal Australian and New Zealand College of Radiologists.)
- Published
- 2018
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32. Cardiac-sparing radiation therapy using positioning breast shell for patients with left-sided breast cancer who are ineligible for breath-hold techniques.
- Author
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Joseph K, Warkentin H, Ghosh S, Polkosnik LA, Powell K, Brennan M, Warkentin B, Jacobs J, Alkaabi K, Chafe S, Tankel K, Gabos Z, Liu HW, and Tai P
- Abstract
Purpose: Patients with left-sided breast cancer (LSBC) are at increased risk of cardiac morbidity from adjuvant breast radiation therapy (ABRT). Breath-hold (BH) techniques substantially reduce the radiation received by heart during radiation therapy for LSBC. However, a subset of patients with LSBC are ineligible for BH techniques due to an inability to breath-hold or because of other comorbidities. To reduce radiation to the heart, we routinely use a custom-made breast shell for the treatment of patients with LSBC who are ineligible for BH techniques. This study evaluates the dosimetric impact of using a breast shell for patients with LSBC undergoing ABRT., Methods and Materials: Sixteen consecutive patients with LSBC who failed BH and underwent ABRT using a breast shell during the period of 2014 to 2016 were identified. Treatment was planned using field-in-field tangents with a prescribed dose of 42.5 Gy in 16 fractions. Comparisons between plans with and without a shell were made for each patient using a paired t test to quantify the sparing of organs at risk (OARs) and target coverage., Results: There was no statistically significant difference in the planning target volume of breast coverage. A statistically significant improvement was observed in sparing the heart, left ventricle (LV), and ipsilateral lung ( P -value < .001). Plans with the shell spared OARs better than the no-shell plans with a mean dose of 2.15 Gy versus 5.15 Gy (58.2% reduction) to the heart, 3.27 Gy versus 9.00 Gy (63.7% reduction) to the LV, and 5.16 Gy versus 7.95 Gy (35% reduction) to the ipsilateral lung. The irradiated volumes of OARs for plans with and without shell are 13.3 cc versus 59.5 cc (77.6% reduction) for the heart, 6.2 cc versus 33.2 cc (81.2% reduction) for the LV, and 92.8 cc versus 162.5 cc (42.9% reduction) for the ipsilateral lung., Conclusions: A positioning breast shell offers significant benefit in terms of sparing the heart for patients with LSBC who are ineligible for BH techniques. It also can be used as a simple cardiac-sparing alternative in centers without BH capability.
- Published
- 2017
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33. Patient reported quality of life after helical IMRT based concurrent chemoradiation of locally advanced anal cancer.
- Author
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Joseph K, Vos LJ, Warkentin H, Paulson K, Polkosnik LA, Usmani N, Tankel K, Severin D, Nijjar T, Schiller D, Wong C, Ghosh S, Mulder K, and Field C
- Subjects
- Adult, Aged, Aged, 80 and over, Antineoplastic Combined Chemotherapy Protocols adverse effects, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Anus Neoplasms therapy, Carcinoma, Squamous Cell therapy, Fecal Incontinence etiology, Female, Fluorouracil administration & dosage, Follow-Up Studies, Humans, Male, Middle Aged, Mitomycin administration & dosage, Psychometrics, Radiotherapy, Intensity-Modulated methods, Surveys and Questionnaires, Urinary Incontinence etiology, Anus Neoplasms rehabilitation, Carcinoma, Squamous Cell rehabilitation, Chemoradiotherapy adverse effects, Quality of Life, Radiotherapy, Intensity-Modulated adverse effects
- Abstract
Background and Purpose: Concurrent chemoradiation (CCRT) is the standard treatment for locally advanced anal canal carcinoma, although treatment-related side effects can affect patient quality of life (QOL). The purpose was to prospectively evaluate the effects of Tomotherapy (HT) based CCRT on patient reported QOL in locally advanced anal cancer., Patients and Methods: Fifty-four patients treated with HT and concurrent 5-fluorouracil/mitomycin-C underwent QOL evaluation at baseline, after treatment, and during follow-up with EORTC core (QLQ-C30) and colorectal (QLQ-CR29) questionnaires. The QOL scores at baseline and post-treatment were compared., Results: All C30 functional symptoms, except emotional and cognitive functioning, were impaired end-of-treatment and recovered by 3months follow-up. The majority of symptom scores were worse end-of-treatment but recovered by 3months except for fecal incontinence (FI), diarrhea, urinary incontinence (UI), and dyspareunia which persisted. FI returned to baseline at 12months while diarrhea, UI, and dyspareunia persisted., Conclusions: Most impaired functions and symptoms following HT based CCRT were temporary and improved by 3months post-therapy. Late complications affecting QOL were FI, sexual function, UI, and diarrhea. Our observations support routine use of IMRT and emphasize the significance of precise evaluation of sexual, urinary, and anorectal functions before starting CCRT and routine incorporation of QOL evaluations., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2016
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34. Survival Outcomes and Patterns of Recurrence in Patients with Stage III or IV Oropharyngeal Cancer Treated with Primary Surgery or Radiotherapy.
- Author
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Debenham BJ, Banerjee R, Warkentin H, Ghosh S, Scrimger R, Jha N, and Parliament M
- Abstract
Purpose: To compare and contrast the patterns of failure in patients with locally advanced squamous cell oropharyngeal cancers undergoing curative-intent treatment with primary surgery or radiotherapy +/- chemotherapy., Methods and Materials: Two hundred and thirty-three patients with stage III or IV oropharyngeal squamous cell carcinoma who underwent curative-intent treatment from 2006-2012, were reviewed. The median length of follow-up for patients still alive at the time of analysis was 4.4 years. Data was collected retrospectively from a chart review., Results: One hundred and thirty-nine patients underwent primary surgery +/- adjuvant therapy, and 94 patients underwent primary radiotherapy +/- chemotherapy (CRT). Demographics were similar between the two groups, except primary radiotherapy patients had a higher age-adjusted Charleston co-morbidity score (CCI). Twenty-nine patients from the surgery group recurred; 15 failed distantly only, seven failed locoregionally, and seven failed both distantly and locoregionally. Twelve patients recurred who underwent chemoradiotherapy; ten distantly alone, and two locoregionally. One patient who underwent radiotherapy (RT) alone failed distantly. Two and five-year recurrence-free survival rates for patients undergoing primary RT were 86.6% and 84.9% respectively. Two and five-year recurrence-free survival rates for primary surgery was 80.9% and 76.3% respectively (p=0.21). There was no significant difference in either treatment when they were stratified by p16 status or smoking status., Conclusions: Our analysis does not show any difference in outcomes for patients treated with primary surgery or radiotherapy. Although the primary pattern of failure in both groups was distant metastatic disease, some local failures may be preventable with careful delineation of target volumes, especially near the base of skull region., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2016
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35. Prospective phase II study of tomotherapy based chemoradiation treatment for locally advanced anal cancer.
- Author
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Joseph K, Nijjar Y, Warkentin H, Schiller D, Tankel K, Usmani N, Severin D, Ghosh S, Syme A, Nijjar T, Mulder K, Doll C, Wong C, and Field C
- Subjects
- Adult, Aged, Aged, 80 and over, Antineoplastic Combined Chemotherapy Protocols adverse effects, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Chemoradiotherapy methods, Disease-Free Survival, Female, Fluorouracil administration & dosage, Humans, Male, Middle Aged, Mitomycin administration & dosage, Prospective Studies, Radiotherapy Dosage, Radiotherapy, Intensity-Modulated methods, Anus Neoplasms therapy, Carcinoma, Squamous Cell therapy, Chemoradiotherapy adverse effects, Radiotherapy, Intensity-Modulated adverse effects
- Abstract
Background and Purpose: To evaluate toxicity, local control, and survival of anal cancer patients treated with helical tomotherapy (HT) and concurrent 5-fluorouracil and mitomycin-C (5FU/MMC)., Materials and Methods: Fifty-seven patients were treated with HT and concurrent 5FU/MMC. The planning objectives were to deliver 54 Gy to the tumor (PTV54) and 45 Gy to the nodes at risk (PTV45) in 30 fractions. Patients were reviewed for toxicity weekly during HT, every 6 weeks for 3 months, and then every 3-4 months for 5 years., Results: The median follow-up was 40 months. The median age was 58 years (range: 37-83). Stage distribution: stage II-48%, IIIA-18%, IIIB-34%. The majority of patients developed ⩽ grade 2 acute toxicity scores. The most common ⩾ grade 3 acute toxicity was neutropenia (40%). Common late toxicities were grade 2 anal incontinence (16%) and telangiectasia (12%). The 3 year colostomy-free survival rate was 77% (95% CI: 61-87%), 3 year disease-free survival rate was 80% (CI: 66-89%), and 3 year overall survival was 91% (CI: 77-96%)., Conclusions: Incorporation of HT with concurrent 5FU/MMC had low treatment-related acute and late morbidity with few treatment breaks. However, the expected dosimetric benefit for hematological toxicity was not experienced clinically., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2015
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36. A Comparative Planning Analysis and Integral Dose of Volumetric Modulated Arc Therapy, Helical Tomotherapy, and Three-dimensional Conformal Craniospinal Irradiation for Pediatric Medulloblastoma.
- Author
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Patel S, Drodge S, Jacques A, Warkentin H, Powell K, and Chafe S
- Abstract
Introduction: The purpose of this study was to compare volumetric modulated arc therapy (VMAT) with helical tomotherapy (HT) and three-dimensional conformal radiation therapy (3D-CRT) for craniospinal irradiation (CSI) in children with medulloblastoma., Methods: Five children treated with 3D-CRT were retrospectively replanned with HT and VMAT. Tomotherapy plans used a single helical arc, thereby eliminating field junctions. VMAT plans used two arcs rotating alternatively clockwise and counterclockwise, respectively. Conformity and homogeneity indices, dose-volume histograms, integral doses, monitor units delivered, and beam-on times were compared., Results: VMAT showed an improved mean conformity index of 1.05 in comparison with 3D-CRT (1.58, P = .04) and HT (1.34, P = .04). The mean homogeneity index of VMAT (1.13) was not significantly different from 3D-CRT (1.16) but higher than HT (1.08, P = .04). For normal tissues, VMAT resulted in a lower mean dose to the skin, eyes, lenses, optic nerves, cochlea, esophagus, heart, peritoneal cavity, bladder, and rectum compared with 3D-CRT (all P = .04). There were few significant differences in dose-volume statistics for normal tissues between VMAT and HT. The mean nontarget tissue integral dose for VMAT of 80.8 J was significantly lower than for 3D-CRT (91.5 J, P = .04) and HT (95.6 J, P = .04). Body and nontarget tissue integral doses were lowest with VMAT in every patient., Conclusions: For CSI, VMAT provides comparable normal tissue sparing with tomotherapy and may reduce the integral dose. Compared with 3D-CRT, VMAT improved normal tissue sparing at higher doses despite larger volumes receiving lower doses. These findings have potential implications in the risk of the development of late adverse effects and radiation-related second malignancies in children with curable primary disease., (Copyright © 2015 Elsevier Inc. All rights reserved.)
- Published
- 2015
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37. Intensity-Modulated Radiotherapy (IMRT) vs Helical Tomotherapy (HT) in Concurrent Chemoradiotherapy (CRT) for Patients with Anal Canal Carcinoma (ACC): an analysis of dose distribution and toxicities.
- Author
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Yeung R, McConnell Y, Warkentin H, Graham D, Warkentin B, Joseph K, and Doll CM
- Subjects
- Adult, Aged, Aged, 80 and over, Anus Neoplasms mortality, Anus Neoplasms pathology, Cisplatin administration & dosage, Female, Fluorouracil administration & dosage, Follow-Up Studies, Gastrointestinal Diseases diagnosis, Gastrointestinal Diseases etiology, Hematologic Diseases diagnosis, Hematologic Diseases etiology, Humans, Male, Middle Aged, Mitomycin administration & dosage, Neoplasm Staging, Prognosis, Radiometry, Radiotherapy Dosage, Radiotherapy Planning, Computer-Assisted methods, Retrospective Studies, Skin Diseases diagnosis, Skin Diseases etiology, Survival Rate, Antineoplastic Combined Chemotherapy Protocols adverse effects, Anus Neoplasms therapy, Chemoradiotherapy adverse effects, Radiotherapy, Intensity-Modulated methods
- Abstract
Purpose: Intensity-modulated radiotherapy (IMRT) and helical tomotherapy (HT) have been adopted for radiotherapy treatment of anal canal carcinoma (ACC) due to better conformality, dose homogeneity and normal-tissue sparing compared to 3D-CRT. To date, only one published study compares dosimetric parameters of IMRT vs HT in ACC, but there are no published data comparing toxicities. Our objectives were to compare dosimetry and toxicities between these modalities., Methods and Materials: This is a retrospective study of 35 ACC patients treated with radical chemoradiotherapy at two tertiary cancer institutions from 2008-2010. The use of IMRT vs HT was primarily based on center availability. The majority of patients received fluorouracil (5-FU) and 1-2 cycles of mitomycin C (MMC); 2 received 5-FU and cisplatin. Primary tumor and elective nodes were prescribed to ≥54Gy and ≥45Gy, respectively. Patients were grouped into two cohorts: IMRT vs HT. The primary endpoint was a dosimetric comparison between the cohorts; the secondary endpoint was comparison of toxicities., Results: 18 patients were treated with IMRT and 17 with HT. Most IMRT patients received 5-FU and 1 MMC cycle, while most HT patients received 2 MMC cycles (p<0.01), based on center policy. HT achieved more homogenous coverage of the primary tumor (HT homogeneity and uniformity index 0.14 and 1.02 vs 0.29 and 1.06 for IMRT, p=0.01 and p<0.01). Elective nodal coverage did not differ. IMRT achieved better bladder, femoral head and peritoneal space sparing (V30 and V40, p ≤ 0.01), and lower mean skin dose (p<0.01). HT delivered lower bone marrow (V10, p<0.01) and external genitalia dose (V20 and V30, p<0.01). Grade 2+ hematological and non-hematological toxicities were similar. Febrile neutropenia and unscheduled treatment breaks did not differ (both p=0.13), nor did 3-year overall and disease-free survival (p=0.13, p=0.68)., Conclusions: Chemoradiotherapy treatment of ACC using IMRT vs HT results in differences in dose homogenity and normal-tissue sparing, but no significant differences in toxicities.
- Published
- 2015
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38. Dosimetric effect of small bowel oral contrast on conventional radiation therapy, linear accelerator-based intensity modulated radiation therapy, and helical tomotherapy plans for rectal cancer.
- Author
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Joseph K, Liu D, Severin D, Dickey M, Polkosnik LA, Warkentin H, Mihai A, Ghosh S, and Field C
- Subjects
- Administration, Oral, Contrast Media, Humans, Particle Accelerators, Radiometry instrumentation, Radiometry methods, Radiotherapy Dosage, Tomography, Spiral Computed instrumentation, Tomography, Spiral Computed methods, Intestine, Small anatomy & histology, Radiotherapy Planning, Computer-Assisted methods, Radiotherapy, Intensity-Modulated methods, Rectal Neoplasms radiotherapy
- Abstract
Purpose: This study evaluated the dosimetric effect of small bowel oral contrast on conventional radiation therapy, linear accelerator-based intensity modulated radiation therapy (IMRT), and helical tomotherapy (HT) treatment plans., Methods and Materials: Thirteen patients with rectal cancer underwent computed tomography (CT) simulation with oral contrast (CCT) in preparation for chemoradiation therapy. The contrast in the small bowel was contoured, and a noncontrast CT scan (NCCT) was simulated by reassigning a CT number of 0 Hounsfield units to the contrast volume. Conventional, IMRT, and HT plans were generated with the CCT. The plan generated on the CCT was then recalculated on the NCCT, maintaining the same number of monitor units for each field, and the plans were not renormalized. Dosimetric parameters representing coverage of the planning target volume with 45 Gy (D98%, D95%, D50%, and D2%) and sparing of the bladder and peritoneal cavity (D50%, D30%, and D10%) were recorded. The ratio of dose calculated in the presence of contrast to dose with contrast edited out was recorded for each parameter. A paired Student t test was used for comparison of plans., Results: For conventional plans, there was <0.1% variance in the dose ratio for all volumes of interest. For IMRT plans, there was a 1% decrease in the mean dose ratio, and the range of dose ratios for all volumes was greater than that for HT or conventional plans. For HT plans, for all volumes of interest, the mean dose ratio was <0.2%, and the range for all patients was <1%. For all IMRT dosimetric parameters, the difference was in the order of 1% of the mean dose (P < .05). The dose difference was not statistically significant for the conventional or HT plans., Conclusions: The use of CCT during CT simulation has no clinically significant effect on dose calculations for conventional, IMRT, and HT treatment plans and may not require replacement of the contrast with a CT number of 0 Hounsfield units., (Copyright © 2015 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2015
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39. Dose-volume analysis of locoregional recurrences in head and neck IMRT, as determined by deformable registration: a prospective multi-institutional trial.
- Author
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Shakam A, Scrimger R, Liu D, Mohamed M, Parliament M, Field GC, El-Gayed A, Cadman P, Jha N, Warkentin H, Skarsgard D, Zhu Q, and Ghosh S
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Algorithms, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Carcinoma, Squamous Cell surgery, Combined Modality Therapy, Disease-Free Survival, Female, Follow-Up Studies, Head and Neck Neoplasms drug therapy, Head and Neck Neoplasms surgery, Humans, Male, Middle Aged, Neoplasm Recurrence, Local, Neoplasm Staging, Parotid Gland radiation effects, Prospective Studies, Radiotherapy Dosage, Treatment Outcome, Carcinoma, Squamous Cell radiotherapy, Head and Neck Neoplasms radiotherapy, Radiotherapy, Intensity-Modulated
- Abstract
Background and Purpose: Although IMRT for head and neck cancer is widely accepted, the implications of sparing normal tissue immediately adjacent to target volumes are not well known., Materials and Methods: Between 2002 and 2007, 124 patients with head and neck cancer were treated with surgery and postoperative IMRT (n=79) or definitive RT (n=45). Locoregional recurrences were analyzed for location relative to target volumes, and dosimetry., Results: With a median follow-up of 26.1months, a total of 16 locoregional recurrences were observed. The five-year actuarial locoregional disease-free survival was 82% [95% CI, 72-90%]. Analysis of 18 distinct sites of locoregional failure revealed that five of these failures were within the high dose clinical target volume (CTV), nine failures were at the margin of the CTV, and four recurrences were outside the CTV. The mean dose delivered to these recurrent volumes was 63.1 Gy [range: 57-68 Gy], while the mean dose to the coolest 1cc within each recurrence was 60.0 Gy [range: 51-67 Gy]. There were two periparotid recurrences observed., Conclusions: We observed excellent locoregional control rates overall. The majority of recurrences occur within high dose regions of the neck and not near the spared parotid glands., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2011
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40. A treatment planning study comparing helical tomotherapy with intensity-modulated radiotherapy for the treatment of anal cancer.
- Author
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Joseph KJ, Syme A, Small C, Warkentin H, Quon H, Ghosh S, Field C, Pervez N, Tankel K, Patel S, Usmani N, Severin D, Nijjar T, Fallone G, and Pedersen J
- Subjects
- Female, Humans, Male, Radiation Dosage, Treatment Outcome, Anus Neoplasms radiotherapy, Radiotherapy, Intensity-Modulated, Tomography, Spiral Computed
- Abstract
Purpose: A planning study to compare helical tomotherapy (HT) and intensity-modulated radiotherapy (IMRT) for the treatment of anal canal cancer., Materials and Methods: Sixteen (8 males and 8 females) patients with anal cancer previously treated radically were identified. HT and IMRT plans were generated and dosimetric comparisons of the plans were performed. The planning goals were to deliver 54Gy to the tumor (PTV(54Gy)) and 48Gy to the nodes at risk (PTV(Node)) in 30 fractions., Results: PTVs: HT plans were more homogeneous for both men and women. Male patients: HT vs. IMRT: D(max): 55.87+/-0.58 vs. 59.17+/-3.24 (p=0.036); D(min): 52.91+/-0.36 vs. 44.09+/-6.84 (p=0.012); female patients: HT vs. IMRT: D(max): 56.14+/-0.71 vs. 59.47+/-0.81 (p=0.012); D(min): 52.36+/-0.87 vs. 50.97+/-1.42 (p=0.028). OARs: In general, HT plans delivered a lower dose to the peritoneal cavity, external genitalia and the bladder and IMRT plans resulted in greater sparing of the pelvic bones (iliac crest/femur) for both men and women. Iliac crest/femur: the difference was significant only for the mean V10Gy of iliac crest in women (p< or =0.012). External genitalia: HT plans achieved better sparing in women compared to men (p< or =0.046). For men, the mean doses were 18.96+/-3.17 and 15.72+/-3.21 for the HT and IMRT plan, respectively (p< or =0.017). Skin: both techniques achieved comparable sparing of the non-target skin (p=NS)., Conclusions: HT and IMRT techniques achieved comparable target dose coverage and organ sparing, whereas HT plans were more homogeneous for both men and women., (Copyright 2009 Elsevier Ireland Ltd. All rights reserved.)
- Published
- 2010
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41. Correlation between saliva production and quality of life measurements in head and neck cancer patients treated with intensity-modulated radiotherapy.
- Author
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Scrimger R, Kanji A, Parliament M, Warkentin H, Field C, Jha N, and Hanson J
- Subjects
- Female, Humans, Male, Middle Aged, Quality of Life, Radiotherapy methods, Radiotherapy Dosage, Xerostomia etiology, Carcinoma, Squamous Cell radiotherapy, Head and Neck Neoplasms radiotherapy, Radiotherapy adverse effects, Salivation radiation effects, Xerostomia diagnosis
- Abstract
Purpose: To investigate the strength of correlation between measured saliva flow rates and various toxicity endpoints commonly used in head and neck cancer (HNC) treatment., Materials and Methods: All patients enrolled in a phase II study using intensity modulated radiotherapy (IMRT) for HNC treatment underwent whole mouth saliva flow measurements (stimulated and unstimulated). They were also assessed for salivary gland toxicity using Radiation Therapy Oncology Group (RTOG) late toxicity grading and 9 items representing patient-graded toxicities from 2 questionnaires (Xerostomia questionnaire and University of Washington quality of life). For each patient, saliva flow rates and quality of life (QOL) data were collected preradiotherapy (RT) and at 3 intervals post-RT (3, 6, and 12 months)., Results: A total of 188 sets of coregistered data were obtained for 47 patients over a period of approximately 4 years. Saliva production and mean QOL dropped significantly immediately after RT, but there was a statistically significant recovery in both parameters between 3- and 12-month post-RT. By 12 months, post-RT the mean QOL scores had returned to pre-RT baseline, although mean stimulated saliva production remained 58% below baseline., Conclusion: Patients with HNC treated with IMRT experienced a small drop in QOL which recovered to baseline by 12 months post-RT. There was no statistically significant correlation seen between global health-related QOL scores and stimulated saliva production rates in the post-RT period.
- Published
- 2007
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42. Experimental validation of the Eclipse AAA algorithm.
- Author
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Breitman K, Rathee S, Newcomb C, Murray B, Robinson D, Field C, Warkentin H, Connors S, Mackenzie M, Dunscombe P, and Fallone G
- Subjects
- Body Burden, Computer Simulation, Humans, Particle Accelerators, Radiotherapy Dosage, Relative Biological Effectiveness, Scattering, Radiation, Algorithms, Models, Biological, Photons therapeutic use, Radiometry methods, Radiotherapy Planning, Computer-Assisted methods
- Abstract
The present study evaluates the performance of a newly released photon-beam dose calculation algorithm that is incorporated into an established treatment planning system (TPS). We compared the analytical anisotropic algorithm (AAA) factory-commissioned with "golden beam data" for Varian linear accelerators with measurements performed at two institutions using 6-MV and 15-MV beams. The TG-53 evaluation regions and criteria were used to evaluate profiles measured in a water phantom for a wide variety of clinically relevant beam geometries. The total scatter factor (TSF) for each of these geometries was also measured and compared against the results from the AAA. At one institute, TLD measurements were performed at several points in the neck and thoracic regions of a Rando phantom; at the other institution, ion chamber measurements were performed in a CIRS inhomogeneous phantom. The phantoms were both imaged using computed tomography (CT), and the dose was calculated using the AAA at corresponding detector locations. Evaluation of measured relative dose profiles revealed that 97%, 99%, 97%, and 100% of points at one institute and 96%, 88%, 89%, and 100% of points at the other institution passed TG-53 evaluation criteria in the outer beam, penumbra, inner beam, and buildup regions respectively. Poorer results in the inner beam regions at one institute are attributed to the mismatch of the measured profiles at shallow depths with the "golden beam data." For validation of monitor unit (MU) calculations, the mean difference between measured and calculated TSFs was less than 0.5%; test cases involving physical wedges had, in general, differences of more than 1%. The mean difference between point measurements performed in inhomogeneous phantoms and Eclipse was 2.1% (5.3% maximum) and all differences were within TG-53 guidelines of 7%. By intent, the methods and evaluation techniques were similar to those in a previous investigation involving another convolution-superposition photon-beam dose calculation algorithm in another TPS, so that the current work permitted an independent comparison between the two algorithms for which results have been provided.
- Published
- 2007
- Full Text
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