1. Hiroshima High‐Precision Radiotherapy Cancer Center 3‐2‐2, Futabanosato, Higashi‐ku Hiroshima 732‐0057 Japan
2. Department of Radiation Oncology Graduate School of Biomedical & Health Sciences Hiroshima University 1‐2‐3 Kasumi, Minami‐ku Hiroshima 734‐8551 Japan
3. Department of Radiation Oncology Hiroshima University Hospital 1‐2‐3 Kasumi, Minami‐ku Hiroshima 734‐8551 Japan
4. Radiation Therapy Section Department of Clinical Support Hiroshima University Hospital 1‐2‐3 Kasumi, Minami‐ku Hiroshima 734‐8551 Japan
5. Department of Radiology Hiroshima Prefectural Hospital 1‐5‐54, Ujinakanda, Minami‐ku Hiroshima 734‐8530 Japan
6. Radiation Therapy Department Hiroshima City Hiroshima Citizens Hospital 7‐33, Motomachi, Naka‐ku Hiroshima 730‐8518 Japan
7. Division of Radiology Hiroshima Red Cross Hospital & Atomic‐bomb Survivors Hospital 1‐9‐6, Senda, Naka‐ku Hiroshima 730‐8619 Japan