RADT-01. GAMMA KNIFE STEREOTACTIC RADIOSURGERY FOR PATIENTS WITH 10 OR MORE BRAIN METASTASES AT INITIAL CNS PRESENTATION

Abstract

Abstract Stereotactic radiosurgery (SRS) is an established treatment modality for patients with up to 10 brain metastases. Previous guidelines have recommended whole brain radiation therapy (WBRT) for patients with > 10 brain metastases, but many providers and patients have opted for SRS in an attempt to minimize neurocognitive toxicity. There is growing literature supporting SRS in patients with ≥ 10 brain metastases in both the up-front and salvage settings. Data remains limited in how to best manage patients with ≥ 10 brain metastases at their first central nervous system (CNS) presentation. A retrospective review was performed on all patients with ≥ 10 brain metastases at their first CNS presentation treated with Gamma Knife SRS since 2010 at our institution. Patients with prior surgery for neurological symptoms were included, but patients who had received prior CNS radiation were excluded. Patients could be treated in a single stage or as many stages necessary to treat all metastases. Demographics and clinical data were collected. Descriptive statistics were used to summarize variables. 91 patients were identified with a median age of 64 years old. The median brain metastases treated was 13 with a range of 10-57. Local failure was 11% and occurred at a median 10.8 months. Distant failure was 51.6% and occurred at a median 2.7 months. 30.8% of patients required repeat SRS and 18.7% of patients required salvage WBRT. Median survival was 7.2 months. 1-year and 2-year overall survival were 34.8% and 16.5%, respectively. Radiation necrosis occurred in 4.4%. Grade 2 toxicity occurred in 36.3% and Grade 3+ toxicity occurred in 7.7%. There were no grade 5 toxicities and only 5.5% of patients died from clear neurological causes. Upfront SRS provides acceptable local control, survival, and toxicity in patients with ≥ 10 metastases at CNS presentation and can be considered for first-line treatment.