1. Department of Radiation Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, #50 Irwon-dong, Gangnam-gu, Seoul 135-710, Korea
2. Department of Medical Device Management and Research, SAIHST, Sungkyunkwan University, Seoul, Korea
3. Department of Radiation Oncology, Peking University First Hospital, Beijing, China
4. Department of Radiation Oncology, Peking University Third Hospital, Beijing, China
5. Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai, China
6. Department of Radiation Oncology, National Cancer Center Hospital, Tokyo, Japan
7. Gunma University Heavy Ion Medical Center, Gunma University, Gunma, Japan
8. Department of Radiation Oncology, Kinki University Faculty of Medicine, Osaka, Japan