14 results on '"Sneed PK"'
Search Results
2. A Prognostic Gene-Expression Signature and Risk Score for Meningioma Recurrence After Resection.
- Author
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Chen WC, Vasudevan HN, Choudhury A, Pekmezci M, Lucas CG, Phillips J, Magill ST, Susko MS, Braunstein SE, Oberheim Bush NA, Boreta L, Nakamura JL, Villanueva-Meyer JE, Sneed PK, Perry A, McDermott MW, Solomon DA, Theodosopoulos PV, and Raleigh DR
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- Adult, Aged, Cohort Studies, Female, Humans, Male, Meningeal Neoplasms pathology, Meningeal Neoplasms surgery, Meningioma pathology, Meningioma surgery, Middle Aged, Multivariate Analysis, Neurosurgical Procedures, Prognosis, Retrospective Studies, Risk Factors, Meningeal Neoplasms genetics, Meningioma genetics, Neoplasm Recurrence, Local genetics, Transcriptome
- Abstract
Background: Prognostic markers for meningioma are needed to risk-stratify patients and guide postoperative surveillance and adjuvant therapy., Objective: To identify a prognostic gene signature for meningioma recurrence and mortality after resection using targeted gene-expression analysis., Methods: Targeted gene-expression analysis was used to interrogate a discovery cohort of 96 meningiomas and an independent validation cohort of 56 meningiomas with comprehensive clinical follow-up data from separate institutions. Bioinformatic analysis was used to identify prognostic genes and generate a gene-signature risk score between 0 and 1 for local recurrence., Results: We identified a 36-gene signature of meningioma recurrence after resection that achieved an area under the curve of 0.86 in identifying tumors at risk for adverse clinical outcomes. The gene-signature risk score compared favorably to World Health Organization (WHO) grade in stratifying cases by local freedom from recurrence (LFFR, P < .001 vs .09, log-rank test), shorter time to failure (TTF, F-test, P < .0001), and overall survival (OS, P < .0001 vs .07) and was independently associated with worse LFFR (relative risk [RR] 1.56, 95% CI 1.30-1.90) and OS (RR 1.32, 95% CI 1.07-1.64), after adjusting for clinical covariates. When tested on an independent validation cohort, the gene-signature risk score remained associated with shorter TTF (F-test, P = .002), compared favorably to WHO grade in stratifying cases by OS (P = .003 vs P = .10), and was significantly associated with worse OS (RR 1.86, 95% CI 1.19-2.88) on multivariate analysis., Conclusion: The prognostic meningioma gene-expression signature and risk score presented may be useful for identifying patients at risk for recurrence., (Copyright © 2020 by the Congress of Neurological Surgeons.)
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- 2020
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3. Letter: Treatment Outcomes and Dose Rate Effects Following Gamma Knife Stereotactic Radiosurgery for Vestibular Schwannomas.
- Author
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Paddick I, Hopewell JW, Klinge T, Graffeo CS, Pollock BE, and Sneed PK
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- Clinical Protocols, Hearing, Humans, Treatment Outcome, Neuroma, Acoustic surgery, Radiosurgery
- Published
- 2020
- Full Text
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4. Temporal Dynamics of Pseudoprogression After Gamma Knife Radiosurgery for Vestibular Schwannomas-A Retrospective Volumetric Study.
- Author
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Breshears JD, Chang J, Molinaro AM, Sneed PK, McDermott MW, Tward A, and Theodosopoulos PV
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- Disease Progression, Humans, Magnetic Resonance Imaging, Retrospective Studies, Neuroma, Acoustic diagnostic imaging, Neuroma, Acoustic epidemiology, Neuroma, Acoustic pathology, Neuroma, Acoustic surgery, Radiosurgery
- Abstract
Background: The optimal observation interval after the radiosurgical treatment of a sporadic vestibular schwannoma, prior to salvage intervention, is unknown., Objective: To determine an optimal postradiosurgical treatment interval for differentiating between pseudoprogression and true tumor growth by analyzing serial volumetric data., Methods: This single-institution retrospective study included all sporadic vestibular schwannomas treated with Gamma Knife radiosurgery (Eketa AB, Stockholm, Sweden; 12-13 Gy) from 2002 to 2014. Volumetric analysis was performed on all available pre- and posttreatment magnetic resonance imaging scans. Tumors were classified as "stable/decreasing," "transient enlargement", or "persistent growth" after treatment, based on incrementally increasing follow-up durations., Results: A total of 118 patients included in the study had a median treatment tumor volume of 0.74 cm3 (interquartile range [IQR] = 0.34-1.77 cm3) and a median follow-up of 4.1 yr (IQR = 2.6-6.0 yr). Transient tumor enlargement was observed in 44% of patients, beginning at a median of 1 yr (IQR = 0.6-1.4 yr) posttreatment, with 90% reaching peak volume within 3.5 yr, posttreatment. Volumetric enlargement resolved at a median of 2.4 yr (IQR 1.9-3.6 yr), with 90% of cases resolved at 6.9 yr. Increasing follow-up revealed that many of the tumors initially enlarging 1 to 3 yr after stereotactic radiosurgery ultimately begin to shrink on longer follow-up (45% by 4 yr, 77% by 6 yr)., Conclusion: Tumor enlargement within ∼3.5 yr of treatment should not be used as a sole criterion for salvage treatment. Patient symptoms and tumor size must be considered, and giving tumors a chance to regress before opting for salvage treatment may be worthwhile.
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- 2019
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5. Surgical Resection and Interstitial Iodine-125 Brachytherapy for High-Grade Meningiomas: A 25-Year Series.
- Author
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Magill ST, Lau D, Raleigh DR, Sneed PK, Fogh SE, and McDermott MW
- Subjects
- Adult, Aged, Combined Modality Therapy, Disease Progression, Female, Follow-Up Studies, Humans, Male, Meningeal Neoplasms radiotherapy, Meningioma radiotherapy, Middle Aged, Neoplasm Recurrence, Local surgery, Prognosis, Retrospective Studies, Treatment Outcome, Brachytherapy, Iodine Radioisotopes therapeutic use, Meningeal Neoplasms surgery, Meningioma surgery
- Abstract
Background: Atypical and malignant meningiomas can recur despite resection and radiation., Objective: To determine outcomes of patients with recurrent atypical or malignant meningioma treated with repeat resection and permanent iodine-125 ( 125 I) brachy-therapy., Methods: Charts of patients who underwent surgical resection and 125 I brachyther-apy implantation for atypical and malignant meningiomas between 1988 and 2013 were retrospectively reviewed. The Kaplan-Meier actuarial method was used to calculate progression-free and overall survival. The log-rank test was used to compare groups. Significance was set at P < .05., Results: Forty-two patients underwent 50 resections with 125 I brachytherapy im-plantations. All patients had undergone previous resections and 85% had previously undergone radiation. Median follow-up was 7.5 years after diagnosis and 2.3 years after brachytherapy. Median time to progression after resection with 125 I brachytherapy was 20.9 months for atypical meningioma, 11.4 months for malignant meningioma, and 11.4 months for the combined groups. Median survival after re-resection and 125 I brachytherapy was 3.5 years for atypical meningioma, 2.3 years for malignant menin-gioma, and 3.3 years for all subjects. Median overall survival after diagnosis was 11.1 years for atypical meningioma, 9.1 years for malignant meningioma, and 9.4 years for all subjects. Complications occurred in 17 patients and included radiation necrosis (n = 8, 16%), wound breakdown (n = 6, 12%), hydrocephalus (n = 4, 8%), infection (n = 3, 6%), and a pseudomeningocele (n = 2, 5%)., Conclusion: This is the largest experience with adjuvant 125 I brachytherapy for recurrent high-grade meningiomas. The outcomes support the use of adjuvant brachytherapy as an option for these aggressive tumors., (Copyright © 2017 by the Congress of Neurological Surgeons)
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- 2017
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6. Indications and Efficacy of Gamma Knife Stereotactic Radiosurgery for Recurrent Glioblastoma: 2 Decades of Institutional Experience.
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Imber BS, Kanungo I, Braunstein S, Barani IJ, Fogh SE, Nakamura JL, Berger MS, Chang EF, Molinaro AM, Cabrera JR, McDermott MW, Sneed PK, and Aghi MK
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- Adult, Aged, Aged, 80 and over, Brain Neoplasms mortality, Brain Neoplasms pathology, Craniotomy, Female, Glioblastoma mortality, Glioblastoma pathology, Humans, Male, Middle Aged, Neoplasm Recurrence, Local mortality, Neoplasm Recurrence, Local pathology, Retrospective Studies, Salvage Therapy, Treatment Outcome, Young Adult, Brain Neoplasms surgery, Glioblastoma surgery, Neoplasm Recurrence, Local surgery, Radiosurgery
- Abstract
Background: The role of stereotactic radiosurgery (SRS) for recurrent glioblastoma and the radionecrosis risk in this setting remain unclear., Objective: To perform a large retrospective study to help inform proper indications, efficacy, and anticipated complications of SRS for recurrent glioblastoma., Methods: We retrospectively analyzed patients who underwent Gamma Knife SRS between 1991 and 2013. We used the partitioning deletion/substitution/addition algorithm to identify potential predictor covariate cut points and Kaplan-Meier and proportional hazards modeling to identify factors associated with post-SRS and postdiagnosis survival., Results: One hundred seventy-four glioblastoma patients (median age, 54.1 years) underwent SRS a median of 8.7 months after initial diagnosis. Seventy-five percent had 1 treatment target (range, 1-6), and median target volume and prescriptions were 7.0 cm 3 (range, 0.3-39.0 cm 3 ) and 16.0 Gy (range, 10-22 Gy), respectively. Median overall survival was 10.6 months after SRS and 19.1 months after diagnosis. Kaplan-Meier and multivariable modeling revealed that younger age at SRS, higher prescription dose, and longer interval between original surgery and SRS are significantly associated with improved post-SRS survival. Forty-six patients (26%) underwent salvage craniotomy after SRS, with 63% showing radionecrosis or mixed tumor/necrosis vs 35% showing purely recurrent tumor. The necrosis/mixed group had lower mean isodose prescription compared with the tumor group (16.2 vs 17.8 Gy; P = .003) and larger mean treatment volume (10.0 vs 5.4 cm 3 ; P = .009)., Conclusion: Gamma Knife may benefit a subset of focally recurrent patients, particularly those who are younger with smaller recurrences. Higher prescriptions are associated with improved post-SRS survival and do not seem to have greater risk of symptomatic treatment effect., (Copyright © 2016 by the Congress of Neurological Surgeons)
- Published
- 2017
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7. Stereotactic radiosurgery for chordoma: a report from the North American Gamma Knife Consortium.
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Kano H, Iqbal FO, Sheehan J, Mathieu D, Seymour ZA, Niranjan A, Flickinger JC, Kondziolka D, Pollock BE, Rosseau G, Sneed PK, McDermott MW, and Lunsford LD
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- Adolescent, Adult, Aged, Aged, 80 and over, Brain Neoplasms mortality, Child, Chordoma mortality, Disease-Free Survival, Female, Humans, Kaplan-Meier Estimate, Male, Middle Aged, Young Adult, Brain Neoplasms surgery, Chordoma surgery, Radiosurgery
- Abstract
Background: Although considered slow-growing, low-grade malignancies, chordomas are locally aggressive and destructive tumors with high recurrence rates., Objective: To assess patient survival, tumor control, complications, and selected variables that predict outcome in patients who underwent Gamma Knife stereotactic radiosurgery (SRS) as primary, adjuvant, or salvage management for chordomas of the skull base., Methods: Six participating centers of the North American Gamma Knife Consortium identified 71 patients who underwent SRS for chordoma. The median patient age was 45 years (range, 7-80 years). The median SRS target volume was 7.1 cm³ (range, 0.9-109 cm³), and median margin dose was 15.0 Gy (range, 9-25 Gy)., Results: At a median follow-up of 5 years (range, 0.6-14 years) after SRS, 23 patients died of tumor progression. The 5-year actuarial overall survival after SRS was 80% for the entire group, 93% for the no prior fractionated radiation therapy (RT) group (n = 50), and 43% for the prior RT group (n = 21). Younger age, longer interval between initial diagnosis and SRS, no prior RT, < 2 cranial nerve deficits, and smaller total tumor volume were significantly associated with longer patient survival. The 5-year treated tumor control rate after SRS was 66% for the entire group, 69% for the no prior RT group, and 62% for the prior RT group. Older age, recurrent group, prior RT, and larger tumor volume were significantly associated with worse tumor control., Conclusion: Stereotactic radiosurgery is a potent treatment option for small sized chordomas, especially in younger patients and as part of a multipronged attack that includes surgical resection when possible.
- Published
- 2011
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8. Radiosurgery in metastatic brain cancer.
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McDermott MW and Sneed PK
- Subjects
- Clinical Trials as Topic, Evidence-Based Medicine, Humans, Neurosurgical Procedures adverse effects, Neurosurgical Procedures methods, Practice Guidelines as Topic, Radiobiology, Radiosurgery adverse effects, Radiosurgery methods, Randomized Controlled Trials as Topic, Retrospective Studies, Brain Neoplasms secondary, Brain Neoplasms surgery, Neurosurgical Procedures trends, Radiosurgery trends
- Abstract
Radiosurgery offers patients with brain metastases an effective and minimally invasive treatment modality. Radiosurgery provides local tumor control and prolongs survival in select patients with brain metastases. This review will discuss numerous aspects of radiosurgery, including the various delivery techniques and radiobiology. Treatment recommendations will be outlined in view of the available clinical data. Although surgery or radiosurgery with whole-brain radiotherapy remains an important option for patients with a solitary brain metastasis, radiosurgery with or without whole-brain radiotherapy should be considered in patients with a limited number of small tumors and a good prognosis.
- Published
- 2005
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9. Surgical resection and permanent brachytherapy for recurrent atypical and malignant meningioma.
- Author
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Ware ML, Larson DA, Sneed PK, Wara WW, and McDermott MW
- Subjects
- Adult, Aged, Female, Humans, Male, Meningeal Neoplasms mortality, Meningioma mortality, Middle Aged, Neoplasm Recurrence, Local mortality, Retrospective Studies, Salvage Therapy, Survival Rate, Treatment Outcome, Brachytherapy, Meningeal Neoplasms radiotherapy, Meningeal Neoplasms surgery, Meningioma radiotherapy, Meningioma surgery, Neoplasm Recurrence, Local radiotherapy, Neoplasm Recurrence, Local surgery
- Abstract
Objective: Recurrent atypical and malignant meningiomas are difficult to treat successfully. Chemotherapy to date has been unsuccessful, and radiosurgery is limited to smaller tumors. Reoperation alone provides limited tumor control and limited prolonged survival. The addition of brachytherapy at the time of operation is an option. Here, we report the results of our series of patients with recurrent malignant meningioma treated with resection and brachytherapy with permanent low-dose (125)I., Methods: The charts of patients in our database with recurrent atypical and malignant meningiomas treated by surgical resection and permanent (125)I brachytherapy at the University of California, San Francisco, between 1988 and 2002 were selected for this study. Calculations of disease-free survival and overall survival curves were made by the Kaplan-Meier actuarial method. Univariate analysis between Kaplan-Meier curves was based on the log-rank statistic, with a significance level set at a value of P = 0.05., Results: Seventeen patients had recurrent malignant meningioma, and four had recurrent atypical meningioma. The median number of sources implanted after surgical resection was 30 (range, 4-112 sources), with a median total activity of 20 mCi (range, 3.3-85.9 mCi). The median time to progression after brachytherapy was 11.6 months for patients with malignant meningioma and 10.4 months for the combined group. There was a trend toward longer disease-free survival time in patients after gross total resection versus subtotal resection and in patients with tumors located at the convexity and parasagittally versus at the cranial base. These differences did not reach statistical significance. The median overall survival after diagnosis was 9.4 years for patients with atypical meningioma, 6.6 years for those with malignant meningioma, and 8.0 years for all patients combined. Survival from the time of resection and implantation of (125)I was 1.6 years for patients with atypical meningioma, 2.4 years for patients with malignant meningioma, and 2.4 years for the combined group. Thirty-three percent of patients had complications requiring surgical intervention. Radiation necrosis occurred in 27% of patients; 13% underwent surgery for radiation necrosis. In addition, 27% had a wound breakdown and required surgical intervention., Conclusion: The options for patients with recurrent atypical or malignant meningiomas are limited. Our results suggest that for tumors not suitable for radiosurgery, resection followed by permanent brachytherapy should be considered as a potential salvage treatment. However, this approach results in a relatively high complication rate in these heavily treated patients and requires meticulous surgical technique and medical therapies to assist with wound healing after surgery.
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- 2004
- Full Text
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10. Age and radiation response in glioblastoma multiforme.
- Author
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Barker FG 2nd, Chang SM, Larson DA, Sneed PK, Wara WM, Wilson CB, and Prados MD
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- Brain Neoplasms diagnostic imaging, Brain Neoplasms mortality, Brain Neoplasms surgery, Cohort Studies, Combined Modality Therapy, Dose Fractionation, Radiation, Glioblastoma diagnostic imaging, Glioblastoma mortality, Glioblastoma surgery, Humans, Odds Ratio, Radiography, Radiotherapy, Adjuvant, Survival Rate, Treatment Outcome, Brain Neoplasms radiotherapy, Cranial Irradiation, Glioblastoma radiotherapy
- Abstract
Objective: Advanced age is a strong predictor of shorter survival in patients with glioblastoma multiforme (GM), especially for those who receive multimodality treatment. Radiographically assessed tumor response to external beam radiation therapy is an important prognostic factor in GM. We hypothesized that older GM patients might have more radioresistant tumors., Methods: We studied radiographically assessed response to external beam radiation treatment (five-level scale) in relation to age and other prognostic factors in a cohort of 301 GM patients treated on two prospective clinical protocols. A total of 223 patients (74%) were assessable for radiographically assessed radiation response. A proportional odds ordinal regression model was used for univariate and multivariate analysis., Results: Younger age (P = 0.006), higher Karnofsky Performance Scale score before radiotherapy (P = 0.027), and more extensive surgical resection (P = 0.028) predicted better radiation response in univariate analyses. Results were similar when clinical criteria were used to classify an additional 61 patients without radiographically assessed radiation response (stable versus progressive disease). In multivariate analyses, age and extent of resection were significant independent predictors of radiation response (P < 0.05); Karnofsky Performance Scale score was of borderline significance (P = 0.07)., Conclusion: Older GM patients are less likely to have good responses to postoperative external beam radiation therapy. Karnofsky Performance Scale score before radiation treatment and extent of surgical resection are additional predictors of radiographically assessed radiation response in GM.
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- 2001
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11. A preliminary study of the prognostic value of proton magnetic resonance spectroscopic imaging in gamma knife radiosurgery of recurrent malignant gliomas.
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Graves EE, Nelson SJ, Vigneron DB, Chin C, Verhey L, McDermott M, Larson D, Sneed PK, Chang S, Prados MD, Lamborn K, and Dillon WP
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- Adult, Aged, Aspartic Acid analogs & derivatives, Aspartic Acid metabolism, Astrocytoma diagnosis, Astrocytoma mortality, Choline metabolism, Creatine metabolism, Female, Glioblastoma diagnosis, Glioblastoma mortality, Humans, Lactic Acid metabolism, Lipid Metabolism, Male, Middle Aged, Neoplasm Recurrence, Local diagnosis, Neoplasm Recurrence, Local mortality, Prognosis, Survival Rate, Astrocytoma surgery, Glioblastoma surgery, Magnetic Resonance Spectroscopy, Neoplasm Recurrence, Local surgery, Radiosurgery
- Abstract
Objective: The goal of this study was to investigate the use of proton magnetic resonance spectroscopic imaging as a prognostic indicator in gamma knife radiosurgery of recurrent gliomas., Methods: Thirty-six patients with recurrent gliomas were studied with proton magnetic resonance spectroscopic imaging at the time of radiosurgery, and with conventional magnetic resonance imaging examinations at regular time intervals until the initiation of a new treatment strategy. Patients were categorized on the basis of their initial spectroscopic results, and their performance was assessed in terms of change in contrast-enhancing volume, time to further treatment, and survival., Results: The trends in the overall population were toward more extensive increase in the percent contrast-enhancing volume, a decreased time to further treatment, and a reduced survival time for patients with more extensive initial metabolic abnormalities. Statistical analysis of the subpopulation of patients with glioblastoma multiforme found a significant increase in relative contrast-enhancing volume (P < 0.01, Wilcoxon signed-rank test), a decrease in time to further treatment (P < 0.01, log-rank test), and a reduction in survival time (P < 0.01, log-rank test) for patients with regions containing tumor-suggestive spectra outside the gamma knife target, compared with patients exhibiting spectral abnormalities restricted to the gamma knife target. Further studies are needed to establish statistical significance for patients with lower-grade lesions and to confirm the results observed in this study., Conclusion: The pretreatment spectroscopic results provided information that was predictive of outcome for this patient pool, both in local control (change in contrast-enhancing volume) and global outcome (time to further treatment and survival). This modality may have an important role in improving the selection, planning, and treatment process for glioma patients.
- Published
- 2000
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12. Large effect of age on the survival of patients with glioblastoma treated with radiotherapy and brachytherapy boost.
- Author
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Sneed PK, Prados MD, McDermott MW, Larson DA, Malec MK, Lamborn KR, Davis RL, Weaver KA, Wara WM, and Phillips TL
- Subjects
- Adolescent, Adult, Aged, Female, Humans, Male, Middle Aged, Multivariate Analysis, Quality of Life, Risk Factors, Survival Analysis, Aging physiology, Brachytherapy, Cerebellar Neoplasms mortality, Cerebellar Neoplasms radiotherapy, Glioblastoma mortality, Glioblastoma radiotherapy
- Abstract
A retrospective review was undertaken to study the influence of age on the survival of patients undergoing brachytherapy boost for glioblastoma multiforme. From February 1981 through December 1992, 159 adults with primary glioblastoma multiforme underwent high-activity iodine-125 brain implant boost after external beam radiotherapy. There were 98 men and 61 women, ranging in age from 18 to 73 years (median, 52 yr). Karnofsky performance scores ranged from 70 to 100 (median, 90). Surgery before radiotherapy consisted of biopsy in 7% of patients, subtotal resection in 66%, and gross total resection in 27%. External beam radiotherapy doses ranged from 39.6 to 76.8 Gy, with 91% of patients receiving 59.4 to 61.2 Gy. Brachytherapy doses ranged from 35.7 to 66.5 Gy (median, 55.0 Gy) at 0.30 to 0.70 Gy per hour (median, 0.43 Gy/h). Reoperations were performed in 81 patients (51%). Information on quality of life was available for 13 of the 14 living 3-year survivors; 10 patients were steroid independent, and mean Karnofsky performance scores had decreased from 92 at the time of brachytherapy to 75 at the last follow-up. Univariate and multivariate analyses showed that age was the most important parameter influencing survival (P < 0.0005). The nine patients 18 to 29.9 years old had a 3-year survival probability of 78 +/- 14% (median survival was not yet reached at the time of this report), with a follow-up of 145 to 511 weeks in living patients (median, 322 wk).(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1995
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13. Interstitial irradiation and hyperthermia for the treatment of recurrent malignant brain tumors.
- Author
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Sneed PK, Stauffer PR, Gutin PH, Phillips TL, Suen S, Weaver KA, Lamb SA, Ham B, Prados MD, and Larson DA
- Subjects
- Adenocarcinoma diagnosis, Adenocarcinoma secondary, Adenocarcinoma therapy, Adult, Aged, Brain Neoplasms diagnostic imaging, Brain Neoplasms mortality, Brain Neoplasms pathology, Combined Modality Therapy, Female, Follow-Up Studies, Humans, Male, Melanoma diagnosis, Melanoma secondary, Melanoma therapy, Middle Aged, Reoperation, Survival Rate, Tomography, X-Ray Computed, Brachytherapy, Brain Neoplasms therapy, Hyperthermia, Induced adverse effects, Neoplasm Recurrence, Local therapy
- Abstract
Between June 1987 and June 1989, 29 recurrent malignant gliomas or recurrent solitary brain metastases in 28 patients were treated in a Phase I study of interstitial irradiation and hyperthermia. Patient age ranged from 18 to 65 years, and the Karnofsky Performance Status scores ranged from 40 to 90%. There were 13 glioblastomas, 10 anaplastic astrocytomas, 3 melanomas, and 3 adenocarcinomas. Catheters were implanted stereotactically after computed tomography-based preplanning. Hyperthermia was administered before and after brachytherapy, using one to six 2450- or 915-MHz helical coil microwave antennas and one to three multisensor fiberoptic thermometry probes. The goal was to heat as much of the tumor as possible to 42.5 degrees C for 30 minutes. Within 30 minutes after the first hyperthermia treatment, implant catheters were afterloaded with high-activity iodine-125 seeds delivering tumor doses of 32.6 to 61.0 Gy. Most patients had no sensation of heating. Complications included seizures in 5 patients, reversible neurological changes in 9 patients, a scalp burn in 1, and infections in 3. Of 28 evaluable 2-month follow-up scans, 11 showed definite improvement in the radiological appearance of the tumor, 4 were slightly improved, 7 were stable, and 6 showed tumor progression. Ten patients underwent reoperation for persistent tumor and/or necrosis. Eleven of 28 patients are alive 40 to 97 weeks after treatment. Thirteen patients died of a brain tumor, 2 died of extracranial melanoma metastases, 1 died of new brain melanoma metastases, and 1 died of a pulmonary embolus. The median survival was 55 weeks overall. Median survival has not yet been reached for the anaplastic astrocytoma subgroup. We conclude that interstitial brain hyperthermia using helical coil microwave antennas is technically feasible. The level of toxicity is acceptable, and the computed tomographic response rate is encouraging.
- Published
- 1991
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14. Interstitial helical coil microwave antenna for experimental brain hyperthermia.
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Satoh T, Seilhan TM, Stauffer PR, Sneed PK, and Fike JR
- Subjects
- Animals, Dogs, Hyperthermia, Induced methods, Microwaves instrumentation, Stereotaxic Techniques, Brain physiology, Brain Diseases therapy, Hyperthermia, Induced instrumentation, Microwaves therapeutic use
- Abstract
A helical coil 2450-MHz microwave antenna was used to induce interstitial hyperthermia in normal dog brain. The HCS-10(1)/11 antenna consisted of a miniature semirigid coaxial cable around which a fine wire coil with 10 turns per 1-cm length was wound. A single antenna and two or three temperature probes were implanted stereotactically, and the temperature distributions surrounding the antenna were measured and compared to those induced using a dipole antenna. The helical coil antenna produced well-localized temperature distributions at depths that were symmetrical around the coil and that extended to the antenna tip. There was minimal variation of the heating patterns with insertion depth using the HCS-10(1)/11 antenna and no excessive heating of extracerebral tissues. In contrast, 2450-MHz dipole antennas induced temperatures of 43 to 46 degrees C at the brain surface and extracerebral tissues (skull, muscle, and scalp), with a relatively uniform but lower temperature in the targeted brain volume. One week after hyperthermia treatment, the thermal lesions induced by the helical coil antenna were visualized using computed tomography. The heating patterns correlated well with the location of the heat lesions and were reproducible among animals. The results indicated that the helical coil antenna could be used to induce localized hyperthermia at specific depths in normal brain without inducing unacceptable heating of the brain surface or extracerebral tissues. Consequently, this antenna seems to be suitable for studying the response of normal brain after a heat insult and may be effective in the application of interstitial microwave brain hyperthermia for malignant brain tumors.
- Published
- 1988
- Full Text
- View/download PDF
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