Gamma knife radiosurgery (GKRS) for pineal region tumors: a study of 147 cases

The purpose of this study is to evaluate the effectiveness of gamma knife radiosurgery (GKRS) in the treatment of pineal region tumors (PRTs). We retrospectively reviewed 147 cases of PRTs primarily treated with GKRS at our hospital between 1999 and 2009. Mean follow-up time was 67 months (range 60.5-100.1). The local tumor control rates (LTCRs) and overall survival rates were calculated to evaluate the results of the GKRS treatment. At 2 months after GKRS, tumor volume was significantly reduced in 91 cases (61.9%). At 6 months, average tumor volume was 4.2 cm(3) as compared to 8.47 cm(3) before GKRS. By 1 year after GKRS, the tumor completely disappeared in 57 patients. Fourteen patients underwent second treatment, and one patient had third treatment. The overall survival rates were 72.1% at 3 years and 66.7% at 5 years for all patients and 62.4% at 3 years and 54.5% at 5 years for germ cell tumors (GCTs). The LTCRs were 94.30% at 3 years and 90.80% at 5 years for all patients and 88.00% at 3 years and 77.27% at 5 years for GCTs. GKRS is an effective and safe modality that can be widely used to PRTs as the primary therapy.