Prognostic Factors for Patients With Brain Metastases Treated With Single-fraction Gamma Knife Radiosurgery

Background/Aim: The aim of this study was to identify prognostic factors for brain metastases treated with Gamma knife radiosurgery. Patients and Methods: Multivariate Cox proportional hazards regression analyses were conducted for patients who received treatment between June 2013 and March 2018. Results: A total of 131 consecutive patients were included. The median follow-up period was 16.0 months (range=1.5-61.5 months). Brain metastases [hazard ratio (HR)=0.42, 95%CI=0.27-0.67, p<0.001], history of systemic therapy (HR=2.23, 95%CI=1.28-3.89, p=0.005), and active extracranial disease (HR=2.49, 95%CI=1.30-4.76, p=0.006) were independent predictors of overall survival. Number of brain metastases (HR=0.39, 95%CI=0.26-0.59, p<0.001) and history of systemic therapy (HR=1.90, 95%CI=1.17-3.08, p=0.005) were independent predictors of intracranial progression-free survival. Conclusion: The number of brain metastases and the history of systemic therapy are associated with patient overall survival and intracranial progression-free survival.