SURVIVAL OUTCOMES AND PROGNOSTIC CONSIDERATIONS OF STEREOTACTIC RADIOSURGERY IN THE TREATMENT OF RECURRENT MALIGNANT GLIOMAS WITH AND WITHOUT BEVACIZUMAB

INTRODUCTION: Stereotactic radiosurgery (SRS) has not proven beneficial in the management of newly diagnosed malignant gliomas (MG), but is used for salvage. Bevacizumab may give an additional benefit to SRS. METHODS: We analyzed 40 consecutive patients treated with SRS alone or with bevacizumab for progressive enhancing lesions. Dose was 25 Gy in 5 fractions over a week. We assessed overall survival from SRS(OS), progression free survival from SRS(PFS), age, gender, lesion volume and location, dexamethasone use, pre-SRS chemotherapeutic and surgical interventions, and bevacizumab use. RESULTS: Initial diagnosis was glioblastoma (GBM) in 25, gliomatosis cerebri 1, anaplastic astrocytomas(AA) 2, oligodendromas(OD) 6, anaplastic oligodendromas(AO) 4, anaplastic oligoastrocytomas(AOA) 1, and epithelial ependyoma(EE) 1. Six-month PFS and twelve-month OS were 51.4% and 48.7%. Median PFS and OS were 5.51 and 12.27 months (m). GBM and AA had OS of 9.5m compared to 28.5m for OD, AOD, and EE (p 40 (p = 0.226). OS was 15.2m for males versus 9.5m for females (p = 0.0612). Frontal and temporal lobe recurrences had OS of 13.1m and 12.3m while parietal and thalamic lesions showed OS of 9.2m and 8.7m. OS was 18.7m for tumor volumes 10cc (p