1. Proton Therapy Center, National Cancer Center, Goyang, Korea.
2. Department of Obstetrics and Gynecology, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea.
3. Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
4. Department of Radiation Oncology, Seoul National University Bundang Hospital, Seongnam, Korea.
5. Department of Radiation Oncology, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Korea.