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GliaSite Brachytherapy for Treatment of Recurrent Malignant Gliomas and Metastases: A Retrospective Single-institutional Analysis
I. J. Radiation Oncology d Biology d Physics
S234
Volume 72, Number 1, Supplement, 2008
(p = 0.09). Multivariate regression analysis showed only dose volumes V8 thru 18 Gy to be significantly predictive of RN, with V8 thru V12 Gy being most predictive (p \ 0.0001). Conclusions: Analysis of patient and treatment variables revealed V8 thru V12 Gy to be significantly predictive for SRN using LINAC based single fraction radiosurgery. This is consistent with data reported for gamma knife radiosurgery. Appropriate patient selection for single dose versus hypofractionated radiosurgery using these data may minimize the risk of RN for patients with brain metastases. Author Disclosure: B.J. Blonigen, None; R.D. Steinmetz, None; S. Maraboyina, None; M.A.S. Lamba, None; R.W. Warnick, None; J.C. Breneman, None.
2144
Semi-continuous Low Dose Rate (LDR) Teletherapy for the Treatment of Recurrent Glial Brain Tumors: Final Report of a Phase I/II Study
M. L. Siker, S. Firat, W. M. Mueller, C. J. Schultz Medical College of Wisconsin, Milwaukee, WI Purpose/Objective(s): Low dose rate (LDR) re-irradiation represents a novel irradiation strategy that exploits the inverse dose rate effect or hyper-radiosensitivity observed in glial cell lines. This technique is thought to produce greater tumor cell killing with reduced normal tissue toxicity due to greater capacity of normal tissues for repair of sub-lethal damage as dose rate is reduced. This is the final report of a prospective Phase I/II study examining patients with recurrent gliomas treated with semi-continuous LDR teletherapy at the Medical College of Wisconsin. Materials/Methods: Patients with recurrent gliomas were enrolled from November 1993 - March 1998. All included patients had pathologically-confirmed gliomas at diagnosis and had previously been irradiated. Patients received semi-continuous LDR radiotherapy, delivered 6 to 8 hours a day at a dose rate of 0.40-0.50 Gy/hour (approximately 3 Gy/fraction daily) for a total dose of 30-35 Gy given over 12 days using a modified Cobalt 60 treatment unit. The frequency of developing unacceptable ($ Grade 3) CNS toxicity within 3 months after LDR treatment was the primary endpoint. Overall survival (OS) was a secondary endpoint. Results: A total of 20 patients (age 22-68) were treated and followed until death with the following histology at diagnosis: 14 with glioblastoma (GBM), 5 with low-grade glioma, and 1 with ependymoma. Two patients did not complete protocol therapy due to tumor progression (1), and discomfort associated with the prolonged treatment (1). No patients developed $ Grade 3 acute CNS toxicity at 3 months in the absence of radiographic evidence of tumor progression. The OS after LDR radiotherapy was 56% at 6-, 28% at 12-, and 17% at 24-months. Two patients survived .48 months, with 1 patient surviving .60 months following LDR treatment. Patients with stable or improved Karnofsky Performance Status (KPS) during the first 3 months had a significantly improved 6-month OS compared to those with worsening KPS (38 vs. 70%, p = 0.0044). Re-resection prior to LDR treatment significantly improved 1-year OS for all patients (44 vs. 11%, p = 0.015) and patients with GBM (43 vs. 0%, p = 0.009). Conclusions: Using LDR teletherapy is safe and effective in patients with recurrent gliomas, resulting in favorable survival in patients who underwent re-resection prior to LDR. More studies are needed to elucidate the role of this method in the treatment of gliomas. Author Disclosure: M.L. Siker, None; S. Firat, None; W.M. Mueller, None; C.J. Schultz, None.
2145
GliaSite Brachytherapy for Treatment of Recurrent Malignant Gliomas and Metastases: A Retrospective Single-institutional Analysis
P. R. Dutta, C. F. Mesina, J. Lopinto, K. Judy, D. O’Rourke, P. LeRoux, M. Ingram, R. Lustig University of Pennsylvania Medical Center, Philadelphia, PA Purpose/Objective(s): To review and assess the efficacy of the GliaSite Radiation Therapy System in the treatment of patients with recurrent malignant gliomas or brain metastases at the Hospital of the University of Pennsylvania. We present here one of the largest single-institutional experiences of using intracranial brachytherapy. Materials/Methods: Between 2001 and 2007, a total of 60 patients with recurrent Grade 3 or 4 gliomas (n = 47) or single intracranial metastases (n = 13) from an extracranial primary tumor were treated with GliaSite. Median age of patients was 56 years. All patients had previously undergone intracranial resection and patients with primary gliomas demonstrated recurrent disease after external beam radiation therapy. All patients underwent maximal surgical debulking of the intracranial lesion and placement of an expandable balloon catheter (GliaSite) in the tumor cavity. The balloon was afterloaded with liquid Iotrex to deliver a median dose of 60 Gy (range, 50-72.5 Gy) to an average depth of 0.5-1 cm with a median dose rate of 50 cGy per hour. Patients were followed with radiological imaging and routine follow-up examinations for tumor progression, side effects, and survival. Further analysis of dose distribution to correlate radiological response, necrosis, or recurrent disease with dose was also undertaken. Results: The median survival for all patients, measured from date of GliaSite placement, was 32 weeks (average 42 weeks) with 25% of patients surviving 1 year or longer. The average survival was 31 weeks for patients with an initial diagnosis of glioblastoma multiforme (GBM) and 47 weeks for those with metastatic disease. No patients were alive with recurrent GBM at 2 years after implant. Four patients treated for intracranial metastases are still alive with greater than 1 year of follow-up. Two patients demonstrated pathologically-documented radiation necrosis after treatment with GliaSite. Conclusions: Although survival after recurrence of primary gliomas remains poor, reirradiation with GliaSite of these tumors after re-resection demonstrated a modest survival benefit above historical controls treated with surgery alone. Author Disclosure: P.R. Dutta, None; C.F. Mesina, None; J. Lopinto, None; K. Judy, None; D. O’Rourke, None; P. LeRoux, None; M. Ingram, None; R. Lustig, None.
S234
Volume 72, Number 1, Supplement, 2008
(p = 0.09). Multivariate regression analysis showed only dose volumes V8 thru 18 Gy to be significantly predictive of RN, with V8 thru V12 Gy being most predictive (p \ 0.0001). Conclusions: Analysis of patient and treatment variables revealed V8 thru V12 Gy to be significantly predictive for SRN using LINAC based single fraction radiosurgery. This is consistent with data reported for gamma knife radiosurgery. Appropriate patient selection for single dose versus hypofractionated radiosurgery using these data may minimize the risk of RN for patients with brain metastases. Author Disclosure: B.J. Blonigen, None; R.D. Steinmetz, None; S. Maraboyina, None; M.A.S. Lamba, None; R.W. Warnick, None; J.C. Breneman, None.
2144
Semi-continuous Low Dose Rate (LDR) Teletherapy for the Treatment of Recurrent Glial Brain Tumors: Final Report of a Phase I/II Study
M. L. Siker, S. Firat, W. M. Mueller, C. J. Schultz Medical College of Wisconsin, Milwaukee, WI Purpose/Objective(s): Low dose rate (LDR) re-irradiation represents a novel irradiation strategy that exploits the inverse dose rate effect or hyper-radiosensitivity observed in glial cell lines. This technique is thought to produce greater tumor cell killing with reduced normal tissue toxicity due to greater capacity of normal tissues for repair of sub-lethal damage as dose rate is reduced. This is the final report of a prospective Phase I/II study examining patients with recurrent gliomas treated with semi-continuous LDR teletherapy at the Medical College of Wisconsin. Materials/Methods: Patients with recurrent gliomas were enrolled from November 1993 - March 1998. All included patients had pathologically-confirmed gliomas at diagnosis and had previously been irradiated. Patients received semi-continuous LDR radiotherapy, delivered 6 to 8 hours a day at a dose rate of 0.40-0.50 Gy/hour (approximately 3 Gy/fraction daily) for a total dose of 30-35 Gy given over 12 days using a modified Cobalt 60 treatment unit. The frequency of developing unacceptable ($ Grade 3) CNS toxicity within 3 months after LDR treatment was the primary endpoint. Overall survival (OS) was a secondary endpoint. Results: A total of 20 patients (age 22-68) were treated and followed until death with the following histology at diagnosis: 14 with glioblastoma (GBM), 5 with low-grade glioma, and 1 with ependymoma. Two patients did not complete protocol therapy due to tumor progression (1), and discomfort associated with the prolonged treatment (1). No patients developed $ Grade 3 acute CNS toxicity at 3 months in the absence of radiographic evidence of tumor progression. The OS after LDR radiotherapy was 56% at 6-, 28% at 12-, and 17% at 24-months. Two patients survived .48 months, with 1 patient surviving .60 months following LDR treatment. Patients with stable or improved Karnofsky Performance Status (KPS) during the first 3 months had a significantly improved 6-month OS compared to those with worsening KPS (38 vs. 70%, p = 0.0044). Re-resection prior to LDR treatment significantly improved 1-year OS for all patients (44 vs. 11%, p = 0.015) and patients with GBM (43 vs. 0%, p = 0.009). Conclusions: Using LDR teletherapy is safe and effective in patients with recurrent gliomas, resulting in favorable survival in patients who underwent re-resection prior to LDR. More studies are needed to elucidate the role of this method in the treatment of gliomas. Author Disclosure: M.L. Siker, None; S. Firat, None; W.M. Mueller, None; C.J. Schultz, None.
2145
GliaSite Brachytherapy for Treatment of Recurrent Malignant Gliomas and Metastases: A Retrospective Single-institutional Analysis
P. R. Dutta, C. F. Mesina, J. Lopinto, K. Judy, D. O’Rourke, P. LeRoux, M. Ingram, R. Lustig University of Pennsylvania Medical Center, Philadelphia, PA Purpose/Objective(s): To review and assess the efficacy of the GliaSite Radiation Therapy System in the treatment of patients with recurrent malignant gliomas or brain metastases at the Hospital of the University of Pennsylvania. We present here one of the largest single-institutional experiences of using intracranial brachytherapy. Materials/Methods: Between 2001 and 2007, a total of 60 patients with recurrent Grade 3 or 4 gliomas (n = 47) or single intracranial metastases (n = 13) from an extracranial primary tumor were treated with GliaSite. Median age of patients was 56 years. All patients had previously undergone intracranial resection and patients with primary gliomas demonstrated recurrent disease after external beam radiation therapy. All patients underwent maximal surgical debulking of the intracranial lesion and placement of an expandable balloon catheter (GliaSite) in the tumor cavity. The balloon was afterloaded with liquid Iotrex to deliver a median dose of 60 Gy (range, 50-72.5 Gy) to an average depth of 0.5-1 cm with a median dose rate of 50 cGy per hour. Patients were followed with radiological imaging and routine follow-up examinations for tumor progression, side effects, and survival. Further analysis of dose distribution to correlate radiological response, necrosis, or recurrent disease with dose was also undertaken. Results: The median survival for all patients, measured from date of GliaSite placement, was 32 weeks (average 42 weeks) with 25% of patients surviving 1 year or longer. The average survival was 31 weeks for patients with an initial diagnosis of glioblastoma multiforme (GBM) and 47 weeks for those with metastatic disease. No patients were alive with recurrent GBM at 2 years after implant. Four patients treated for intracranial metastases are still alive with greater than 1 year of follow-up. Two patients demonstrated pathologically-documented radiation necrosis after treatment with GliaSite. Conclusions: Although survival after recurrence of primary gliomas remains poor, reirradiation with GliaSite of these tumors after re-resection demonstrated a modest survival benefit above historical controls treated with surgery alone. Author Disclosure: P.R. Dutta, None; C.F. Mesina, None; J. Lopinto, None; K. Judy, None; D. O’Rourke, None; P. LeRoux, None; M. Ingram, None; R. Lustig, None.