1. Department of Health Sciences and Technology Faculty of Health Sciences Hokkaido University Sapporo Japan
2. Proton Beam Therapy Center Hokkaido University Hospital Sapporo Japan
3. Department of Radiation Medical Science and Engineering Faculty of Medicine Hokkaido University Sapporo Japan
4. Global Station for Quantum Medical Science and Engineering Global Institution for Collaborative Research and Education (GI‐CoRE) Hokkaido University Sapporo Japan
5. Department of Radiation Oncology Faculty of Medicine Hokkaido University Sapporo Japan
6. Faculty of Engineering Hokkaido University Sapporo Japan
7. Department of Statistical Data Science The Institute of Statistical Mathematics Tokyo Japan
8. Department of Proton Beam Therapy Research Center for Cooperative Projects Faculty of Medicine Hokkaido University Sapporo Japan