Linear accelerator based stereotactic radiosurgery for melanoma brain metastases

Abstract

Melanoma is one of the most common malignancies to metastasize to the brain. Many patients with this disease will succumb to central nervous system (CNS) disease, highlighting the importance of effective local treatment of brain metastases for both palliation and survival of the disease. Our objective was to evaluate the outcomes associated with stereotactic radiosurgery (SRS) in the treatment of melanoma brain metastases. We retrospectively reviewed 54 patients with a total of 103 tumors treated with SRS. Twenty patients had prior surgical resection and nine patients underwent prior whole brain radiation therapy (WBRT). 71% of patients had active extracranial disease at the time of SRS. Median number of tumors treated with SRS was 1(range: 1-6) with median radiosurgery tumor volume 2.1 cm 3 (range: 0.05-59.7 cm 3 ). The median dose delivered to the 80% isodose line was 24 Gy in a single fraction. The median follow-up from SRS was five months (range:1-30 months). Sixty-five percent of patients had a follow-up MRI available for review. Actuarial local control at six months and 12 months was 87 and 68%, respectively. Eighty-one percent of patients developed new distant brain metastases at a median time of two months. The six-month and 12-month actuarial overall survival rates were 50 and 25%, respectively. The only significant predictor of overall survival was surgical resection prior to SRS. Post-SRS bleeding occurred in 18% of patients and at a median interval of 1.5 months. There was only one episode of radiation necrosis with no other treatment-related toxicity. SRS for brain metastases from melanoma is safe and achieves acceptable local control.