Gamma knife radiosurgery and brain metastases: local control, survival, and quality of life

Object. The purpose of this paper was to describe the clinical outcome in patients with brain metastases who underwent gamma knife radiosurgery (GKS). Methods. The authors retrospectively reviewed the clinical courses of 54 patients with brain metastases who underwent 62 GKS procedures. This series covered a 43-month period. A total of 174 lesions were treated: 38 patients harbored solitary whereas 24 patients harbored multiple metastases. The authors assessed outcome by examining local disease control, survival, and quality of life. The overall local control rate was 85%; the mean time to failure of local control was 10.5 months; and median survival was 8.4 months. Median survival, evaluated by the log-rank test, was greater among patients with a single metastasis (p = 0.043), breast cancer (p = 0.021), and those who had undergone multiple GKS procedures for local failure (p = 0.009). The initial Karnofsky Performance Scale (KPS) score and whole-brain radiotherapy were not significantly related to median survival. The KPS scores tended to remain stable through the follow-up period. There were no morbidities or deaths attributable to the procedure. Conclusions. Results in this series suggest that GKS can be an effective tool for the control of brain metastases. A prospective investigation should be performed to validate trends seen in this retrospective study.