1. Proton Therapy Center National Cancer Center Korea Gyeonggi‐do Republic of Korea
2. Department of Radiation Oncology National Medical Center Seoul Republic of Korea
3. Department of Radiation Oncology Yonsei Cancer Center Yonsei University College of Medicine Seoul Republic of Korea
4. Department of Neurosurgery Inje University Ilsan Paik Hospital Gyeonggi‐do Republic of Korea
5. Department of Radiation Oncology Seoul National University Hospital Seoul Republic of Korea
6. Department of Radiation Convergence Engineering Yonsei University Gangwon‐do Republic of Korea