1. Department of Radiology, Dokkyo Medical University Saitama Medical Center, 2-1-50 Minamikoshigaya, Koshigaya, Saitama 343-8555, Japan
2. Department of Radiation Oncology, Kobe Proton Center, 1-6-8 Minatojima Minamimachi, Chuo-ku, Kobe 650-0047, Japan
3. Department of Cardiology, Faculty of Medicine, University of Tsukuba, Department of Cardiology, 1-1–1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
4. Department of Radiation Medical Science and Engineering, Hokkaido University Faculty of Medicine, Kita 15-jo Nishi 7-chome, Kita-ku, Sapporo 060-8638, Japan
5. Departments of Radiology, Yokohama City University Graduate School of Medicine, 22-2 Seto, Kanazawa-ku, Yokohama, Kanagawa 236-0027, Japan
6. Department of Radiation Oncology, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan
7. Department of Radiology, Aichi Medical University Hospital, 1-1 Yazakokarimata, Nagakute, Aichi 480-1195, Japan
8. Ibaraki Prefectural Central Hospital and Cancer Center, 6528 Koibuchi, Kasama, Ibaraki 309-1793, Japan
9. Department of Radiation Oncology, Kagawa University Hospital, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa, 761-0793 Japan
10. Department of Radiation Oncology, Hyogo Cancer Center, 1-2-1 Koto, Shingu-cho, Tatsuno-shi, Hyogo 679-5165, Japan
11. Department of Radiology, Jichi medical university, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan
12. Department of Radiation Oncology, Kawasaki Medical School, 577 Matsushima, Kurashiki, Okayama 701-0192, Japan