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

Background: The purpose of this study is to evaluate the effectiveness of gamma knife radiosurgery (GKRS) in the treatment of pineal region tumors (PRTs). Methods: 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. Results: 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. Conclusions: GKRS is an effective and safe modality that can be widely used to PRTs as the primary therapy.