1. Department of Radiation Oncology, Yonsei University College of Medicine, Seoul
2. Department of Radiation Oncology, Inha University Hospital, Incheon
3. Department of Surgery, Yonsei University College of Medicine
4. Division of Gastroenterology, Department of Internal Medicine, Yonsei University College of Medicine
5. Division of Medical Oncology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea