The role of stereotactic radiosurgery in the treatment of renal cell carcinoma patients with five or more brain metastases.

Abstract

410 Background: Whole brain radiation therapy (WBRT) is considered standard treatment in patients with multiple brain metastases (BM). However, WBRT has limited efficacy in patients with BM from radio resistant tumors like renal cell carcinoma (RCC) where median survival is 2–4 months. The aim of this study is to evaluate outcomes in RCC patients with ≥5 BM treated with Stereotactic Radio-surgery (SRS) monotherapy or as part of a multimodality regimen. Methods: Data from 16 consecutive RCC patients with ≥5 simultaneous BM (99 lesions) treated with SRS at our institution (1999–2010) were analyzed. Patient demographics, tumor characteristics, treatment related factors and outcomes were statistically evaluated. Results: 12 male and 4 female patients (median age of 59) were treated. 62% of patients had concurrent systemic metastases to multiple organs at the time of treatment. 31% of patients were on active systemic treatment before SRS. Patients had prior cranial surgery 2(12%), WBRT 6(37%) and SRS 2(12%) previous to their presentation with ≥5 BM. Median interval between primary diagnoses and SRS was 2years (range 0–16). At the time of current SRS treatment 75% of patients had only mild neurological symptoms and median KPS was 80; 87% of patients were Recursive Partitioning Analysis Class II. Median number of lesion was 5 (max 10), and median total intracranial disease burden was 2cc (range 0.2–36.4). Post SRS for ≥5 BM, 9 of 16 patients required further intracranial therapy for new lesions, WBRT 3(19%) and SRS 6(37%). Mean follow up was 6.5 months from SRS for ≥5 BM (range 1-19). 12 patients (75%) died during follow up with neurological cause of death in 3(25%). Median overall survival (OS) was 7.1 months (range1–21). OS was 50% after 6 month and 31% after 1 year. Local control rate was achieved in 91% of targets in all evaluated patients. Conclusions: SRS is traditionally used to treat patients with a limited number of BM. This is the first series to evaluate the role of SRS in the management ≥5 BM in RCC. We demonstrate that using SRS in these patients results in excellent local disease control (91%) and acceptable OS. Hence, SRS should be considered in the ongoing management of patients even with extensive intracranial disease.