1. Southern Tohoku BNCT Research Center, 7-10 Yatsuyamada, Koriyama, 963-8052, Japan
2. Department of Radiation Oncology, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki, 036-8562, Japan
3. Department of Radiation Oncology, Southern Tohoku Proton Therapy Center, 7-172 Yatsuyamada, Koriyama, 963-8052, Japan
4. School of Health Sciences, Fukushima Medical University, 10-6 Sakaemachi, Fukushima, 960-8516, Japan