1. Department of Radiology, Seoul National University Hospital, Seoul, Korea.
2. Department of Radiology, Seoul National University College of Medicine, Seoul, Korea.
3. Institution of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea.
4. Department of Surgery, Seoul National University Hospital, Seoul, Korea.
5. Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.
6. Department of Radiation Oncology, Seoul National University Hospital, Seoul, Korea.