Differentiation of the Radiation-Induced Necrosis and Tumor Recurrence after Gamma Knife Radiosurgery for Brain Metastases: Importance of Multi-Voxel Proton MRS - Chernov, M; Hayashi, M; Izawa, M; Ochiai, T; Usukura, M; Abe, K; Ono, Y; Muragaki, Y; Kubo, O; Hori, T; Takakura, K (min - Minimally Invasive Neurosurgery, 2005)