1. Department of Radiology Nagoya University Graduate School of Medicine Nagoya Aichi Japan
2. Proton Therapy Center Fukui Prefectural Hospital Fukui Japan
3. Department of Radiotherapy Graduate School of Medical Science Kanazawa University Ishikawa Japan
4. Research and Development Division The Wakasa Wan Energy Research Center Fukui Japan
5. Department of Surgery Fukui Prefectural Hospital Fukui Japan