1. Department of Neurosurgery, Kyorin University Faculty of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo
2. Department of Neurosurgery, The Japanese Red Cross Medical Center, 4-1-20 Hiroo, Shibuya, Tokyo
3. Department of Neurosurgery, Kyorin University Graduate School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo
4. Department of Brain Tumor Translational Research, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo, Japan