1. Department of Radiation Oncology, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea.
2. Department of Radiation Oncology, Pusan National University Yangsan Hospital, Yangsan, Korea.
3. Department of Medical Oncology, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea.
4. Department of Radiology, Seoul St. Mary's Hospital, The Catholic University of Korea College of Medicine, Seoul, Korea.
5. Department of Radiation Oncology, Incheon St. Mary's Hospital, The Catholic University of Korea College of Medicine, Incheon, Korea.
6. Department of Radiation Oncology, Uijeongbu St. Mary's Hospital, The Catholic University of Korea College of Medicine, Uijeongbu, Korea.