Melanoma brain metastases: the outcome of whole brain radiation therapy in the era of effective systemic therapy

Abstract

Background: Whole brain radiation therapy (WBRT) is sometimes recommended for patients with multiple melanoma brain metastases (MBM) in addition to systemic therapy and/or local therapy. We report outcomes of WBRT and identify associated factors in the era of modern systemic therapy. Methods: Ninety patients treated with WBRT between 2011 and 2018 were included. Records were analyzed for clinical and treatment characteristics, radiation techniques, systemic therapy and outcomes. Overall survival (OS) rates were calculated using the Kaplan-Meier method; factors affecting OS were assessed using the log-rank test as well as Cox regression. Results: The median age was 63 years and the median follow-up was 4.5 months. The median OS from diagnosis of MBM was 8 months (range, 1–83 months), median OS from the beginning of WBRT was 5 months (range, 0–64 months). Patients with BRAF mutation who had prior systemic treatment (n=31) had a median OS from WBRT of 4.6 versus 5.2 months for those with BRAF wild type disease (n=27). Patients with no systemic treatment prior to WBRT (n=32) had a median survival of 6.7 months (P=0.65). In multivariable analysis, the presence of neurological symptoms was associated with worse OS (P=0.029) and prior surgery with better OS (P=0.002). Conclusions: In selected patients with MBM treated with systemic therapy with known intracranial activity, WBRT is a treatment option in selected patients after local therapy (surgery and SRS). Future studies should further determine the role of systemic treatment in combination with radiotherapy (RT) in MBM patients, particularly in patients with multiple brain metastases. 16