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. Department of Radiation Oncology, Saitama Medical Center, 4-9-3 Kitaurawa, Urawa-ku, Saitama-shi, Saitama, 330-0074, 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, Sakai City Medical Center, 1-1-1 Ebaraji-cho, Nishi-ku, Sakai-shi, Osaka, 593-8304, Japan
6. Department of Radiology, Kindai University Nara Hospital, 1248-1 Otoda-cho, Ikoma-shi, Nara, 630-0293, Japan
7. Department of Radiology, Gifu University School of Medicine, 1-1 Yanagido, Gifu-shi, Gifu, 501-1194, Japan
8. 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
9. Sonoda-kai Radiation Oncology Clinic, 3-4-19 Hokima, Adachi-ku, Tokyo, 121-0064, Japan
10. Department of Radiology, Teikyo University Mizonokuchi Hospital, 5-1-1 Futako, Takatsu, Kawasaki-shi, Kanagawa, 213-8507, Japan
11. Department of Radiology, Toho University Omori Medical Center, 6-11-1 Omori-nishi, Ota-ku, Tokyo, 143-8541, Japan
12. Department of Radiation Oncology, Hamamatsu University Hospital, 1-20-1 Handayama, Higashi-ku, Hamamatsu-shi, Shizuoka, 431-3192, Japan
13. Division of Radiation Oncology, Shizuoka Cancer Center Hospital, 1007 Shimonagakubo, Nagaizumi-cho, Sunto-gun, Shizuoka, 411-8777, Japan
14. Department of Radiation Oncology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita-shi, Osaka, 565-0871, Japan