Department of Radiation Oncology;
China Medical University Hospital;
Department of Medicine;
Taipei Veterans General Hospital;
Division of Hematology and Oncology;
Division of Cardiology;
Department of Medicine;
Taipei Veterans General Hospital;
Department of Family Medicine;
Taipei Veterans General Hospital;
Department of Oncology;
Taipei Veterans General Hospital;
Institute of Public Health;
National Yang-Ming University;
Radiotherapy; second; primary; malignancy; rectal; cancer; preoperative; long-course; preoperative; short-course;