Gamma Knife Radiosurgery for Resectable Brain Metastasis

BackgroundSurgical resection is most often performed for superficially located brain metastasis. We evaluate the use of gamma knife radiosurgery (GKS) for resectable non–small cell lung cancer (NSCLC) brain metastases located <3 cm away from the outer cortical surface.MethodsBetween 1999 and 2009, 306 patients were treated for brain metastasis from NSCLC at the University of Virginia. The current study included patients with 3 or fewer resectable brain metastases, with resectable being defined as <3 cm from the nearest outer cortical surface of the brain. Sixty-four patients with 111 metastatic brain lesions were eligible for the study. Survival, tumor control, and need for a craniotomy and tumor resection after GKS were evaluated.ResultsThe mean overall survival rate in this cohort is 13.5 months (median, 8 months) after GKS, and the mean overall survival after diagnosis of the primary lesion was 31.5 months (median, 19 months). Factors related to prolonged survival after GKS were gender, Karnofsky performance score (KPS), recursive partitioning analysis (RPA) class, age at GKS, number of metastatic lesions, development of new intracranial lesions, and number of lobes involved with metastatic disease. The actuarial local tumor control rate was 84% at 6 months. Two patients (3%) underwent a craniotomy and tumor resection for their progressive superficial metastasis after GKS.ConclusionsGKS for NSCLC brain metastases is effective in patients with 3 or fewer resectable tumors. The need for a craniotomy in this subgroup of patients after GKS is very low.