1. Department of Functional Diagnostic Science, Osaka University Graduate School of Medicine, 1-7 Yamadaoka, Suita-shi, Osaka, 565-0871, Japan
2. Department of Radiation Oncology, Osaka International Cancer Institute, 3-1-69 Otemae, Chuo-ku, Osaka-shi, Osaka, 541-8567, Japan
3. Division of Radiation Oncology, Shizuoka Cancer Center Hospital, 1007 Shimonagakubo, Nagaizumi-cho, Sunto-gun, Shizuoka, 411-8777, Japan
4. Department of Radiology, Japanese Red Cross Otsu Hospital, 1-1-35 Nagara, Otsu-shi, Siga, 520-0000, Japan
5. Department of Radiation Oncology, Saitama Medical Center, 4-9-3 Kitaurawa, Urawa-ku, Saitama-shi, Saitama, 330-0074, Japan
6. Department of Radiation Oncology, Sakai City Medical Center, 1-1-1 Ebaraji-cho, Nishi-ku, Sakai-shi, Osaka, 593-8304, Japan
7. Department of Radiology, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya-shi, Hyogo, 663-8501, Japan
8. Department of Medical Physics and Engineering, Osaka University Graduate School of Medicine, 1-7 Yamadaoka, Suita-shi, Osaka, 565-0871, Japan
9. Division of Medical Quantum Science, Department of Health Sciences, Kyushu University Faculty of Medical Sciences, 3-1-1 Maidashi, Higashi-ku, Fukuoka-shi, Fukuoka, 812-8582, Japan
10. Sonoda-kai Radiation Oncology Clinic, 3-4-19 Hokima, Adachi-ku, Tokyo, 121-0064, Japan
11. Department of Radiology, Teikyo University Mizonokuchi Hospital, 5-1-1 Futako, Takatsu, Kawasaki-shi, Kanagawa, 213-8507, Japan
12. Department of Radiology, Toho University Omori Medical Center, 6-11-1 Omori-nishi, Ota-ku, Tokyo, 143-8541, Japan
13. Department of Radiation Oncology, Hamamatsu University Hospital, 1-20-1 Handayama, Higashi-ku, Hamamatsu-shi, Shizuoka, 431-3192, Japan
14. Hokkaido Cancer Center, 2-3-54 Kikusui 4jyo, Shiraishi-ku, Sapporo-shi, Hokkaido, 003-0804, Japan
15. Southern TOHOKU Proton Therapy Center, 172-7 Yatsuyamada, Koriyama-shi, Fukushima, 963-8563, Japan
16. Department of Radiology and Radiation Oncology, Aichi Medical University, 1-1 Yazakokarimata, Nagakute-shi, Aichi, 480-1195, Japan
17. Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-shi, Osaka, 565-0871, Japan