1. Department of Radiation Oncology, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea.
2. Department of Radiation Oncology, Proton Therapy Center, Research Institute and Hospital, National Cancer Center, Goyang, Korea.
3. Department of Radiation Oncology, Chonnam National University Hwasun Hospital, Hwasun, Korea.
4. Department of Radiation Oncology, Dong-A University Hospital, Dong-A University College of Medicine, Busan, Korea.
5. Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
6. Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
7. Department of Radiation Oncology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, Korea.
8. Department of Radiation Oncology, Gachon University Gil Medical Center, Incheon, Korea.
9. Department of Radiation Oncology, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea.
10. Department of Radiation Oncology, Ewha Womans University Mokdong Hospital, Seoul, Korea.
11. Department of Radiation Oncology, CHA Bundang Hospital, CHA University College of Medicine, Seongnam, Korea.