1 Division of Radiation Oncology Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan; Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital Yunlin Branch, Yunlin, Taiwan; National Taiwan University Cancer Center, Taipei, Taiwan.
2 Division of Radiation Oncology Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan; Cancer Research Center, College of Medicine, National Taiwan University, Taipei, Taiwan; Graduate Institute of Oncology, College of Medicine, National Taiwan University, Taipei, Taiwan; National Taiwan University Cancer Center, Taipei, Taiwan.
3 Division of Colorectal Surgery, Department of Surgery, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan.
4 Division of Radiation Oncology Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan; National Taiwan University Cancer Center, Taipei, Taiwan; Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital Hsinchu Branch, Hsinchu, Taiwan. Electronic address: yhchen@ntuh.gov.tw.