Background: Of the approximately 1,100 new cases of rectal cancer in Norway annually, many can be cured by surgery alone, but a large group of patients need supplemental treatment. We here present the national consensus for radiotherapy of rectal cancer.
Material and methods: This review is based on relevant publications up to April 2007, the authors' own research and clinical experiences, data from The Norwegian Colorectal Cancer Register and guidelines from The Norwegian Gastrointestinal Cancer Group.
Results and interpretation: It is important to discuss these patients in multidisciplinary teams (surgeon, oncologist, radiologist and preferably pathologist). Indications for preoperative radiotherapy are T4-tumours, tumours independent of the T-stadium that threaten the mesorectal fascie (3 mm or less from the tumour) or a pathologic lymph node in mesorectum. The indication for postoperative radiotherapy is perioperative perforation of a tumour or a R1-resection, i.e. histologically verified circumferential resection margin less than 2 mm. The radiotherapy is given in 2 Gy fractions over 25 days concomitant with chemotherapy.