1. Human Health Sciences Graduate School of Medicine Kyoto University 53 Kawahara‐cho, Shogoin, Sakyo‐ku Kyoto 606‐8507 Japan
2. Division of Clinical Radiology Service Kyoto University Hospital 54 Kawahara‐cho, Shogoin, Sakyo‐ku Kyoto 606‐8507 Japan
3. Radiation Oncology and Image‐applied Therapy Graduate School of Medicine, Kyoto University 54 Kawahara‐cho, Shogoin, Sakyo‐ku Kyoto 606-8507 Japan