RTHP-36. CS 131 BRACHYTHERAPY FOR SALVAGE OF RECURRENT BRAIN TUMORS

Abstract

AIM: Effective treatments for recurrent, previously irradiated intracranial neoplasms are limited. For this reason, we decided to study the combination of maximum safe resection and adjuvant radiation using permanent intracranial brachytherapy (S+BT) with implanted Cs -131 sources in modular carriers in this cohort of patients. METHODS: Between 5/2013 and 11/2016 58 recurrent, previously irradiated tumors (High Grade Glioma 41%, Meningioma 40%, and Metastases 19%) in 55 patients (31 males and 24 females) were treated on a single arm Institutional Review Board (IRB) approved trial of surgery and permanent implanted brachytherapy (S+BT) utilizing Cs-131 sources imbedded in modular collagen carriers/spacers that were implanted in the operative bed at the completion of maximally safe resection. Radiation dose prescribed was 60-80 Gy at 5 mm deep to the operative bed. Kaplan-Meier analysis (Log rank tests) was used to model time to local tumor progression. All patients had previously undergone same site surgery (range of 1-4 craniotomies) and radiation therapy (range 1-3 courses). RESULTS: At a median follow-up for the whole group of 10.8 months and living patients of 10.95 months (N=29) respectively, twelve patients (20 %) had local recurrence at an average of 11.33 months (range 2.3- 29.13 months) post implant. Six and 12 months local recurrence free survival is 91 % and 81 % respectively. Six and 12 months Progression Free Survival (PFS) (counting death and local recurrence as events) is 75 % and 61 % respectively. Five patients (11%) had Grade 3 or higher complications, with wound infection/ dehiscence in 4 patients and 1 patient with radiation necrosis treated with laser ablation. CONCLUSION: Surgery and brachytherapy using Cs131seeds imbedded in modular carriers appears to be a safe and effective salvage therapy for patients with recurrent, previously irradiated intracranial tumors.