Rectum and Anal Canal

The purpose of conservative treatment is the control of rectal carcinoma without bowel resection. Conservative treatment by irradiation has long been a subject of controversy, because it contradicts two generally held notions: first, that adenocarcinoma of the rectum is only slightly radiosensitive; second, that rectal cancer can only be cured by radical surgery, i.e., en bloc resection of the bowel segment bearing the tumor and the lymphatic drainage areas.