Gamma knife radiosurgery for simultaneous multiple metastatic brain tumors

Object. The authors assessed the efficacy of gamma knife radiosurgery (GKS) in the treatment of patients with 10 or more simultaneous metastatic brain tumors. Methods. Gamma knife radiosurgery was performed for the treatment of 10 or more simultaneous metastatic brain tumors in 24 patients. The performance status before and after GKS was expressed using the Karnofsky Performance Scale (KPS). The cumulative survival rate was analyzed using the Kaplan-Meier method. The level of satisfaction with the procedure was assessed by telephone interview. No patient has died due to brain metastasis-related symptoms, and all patients and/or their families were satisfied with the GKS. In 12 patients who had brain metastasis-related symptoms, five improved, six were unchanged, and one deteriorated, as reflected by the KPS scores. The cumulative survival rate calculated by the Kaplan-Meier method was 70.4%, 49.3%, and 12.3% at 12 weeks, 24 weeks, and 36 weeks, respectively. The median survival time was 11 weeks. Conclusions. Single-fraction GKS can achieve acceptable tumor control, low morbidity, and good quality of life in the treatment of multiple metastatic brain tumors even in cases with 10 or more simultaneous metastases.