Outcomes Following Hypofractionated Stereotactic Radiotherapy in the Management of Brain Metastases.

Abstract

To evaluate the outcomes of patients treated with hypofractionated stereotactic radiotherapy (HSRT) for radiosensitive and radioresistant brain metastases. Between August 2006 and July 2013, a total of 56 lesions in 44 patients with brain metastases were treated with HSRT. Twenty-three (41.1%) lesions were radioresistant. Patients were treated to a total dose of 24 to 30 Gy in 3 to 5 fractions. Median planning target volume was 6.18 cm. The primary endpoint for this study was local control with secondary endpoints of overall survival, distant failure, performance status, and treatment toxicity. The median follow-up for all patients was 5 months (range, 0.4 to 58.3 mo). Six- and 12-month Kaplan-Meier estimates of local control for all lesions were 85.6% and 79.4%, respectively. Radioresistant tumors had a 6- and 12-month local control rate of 87.0%, whereas radiosensitive tumors had a 6- and 12-month local control rate of 82.5% and 72.2%, respectively (P=0.41). Six- and 12-month distant brain control rates were 56.8% and 46.9%, respectively. Overall survival was significantly associated with recursive partitioning analysis classes I, II, and III (P=0.0003) and graded prognostic assessment classes 2 to 3 and 1 to 1.5 (P=0.041). HSRT is a safe and feasible alternative to single-session stereotactic radiosurgery for brain metastases. No difference was observed in local control rates between radioresistant and radiosensitive tumors.