[Radiotherapy of cancer of the rectum]

As soon as there is a tumor extension into the perirectal fibro fatty tissue (T3 stage) the chance to cure the rectal cancer is no more than 65%. The aim of adjuvant treatment is to reduce the risk of local recurrence and metastasis. Postoperative irradiation does not have a definitive effect on local control, and its tolerance is poor; it may not be recommended. The efficacy of combined postoperative irradiation and chemotherapy has not been definitively proved. Moreover, this approach leads to high toxicities and may not be recommended routinely. On the contrary, preoperative irradiation definitely improves the local control, reducing the risk of recurrence up to 50%. It is commonly indicated as soon as the rectal cancer is at the T3 stage. The efficacy of combined preoperative irradiation and chemotherapy is under evaluation. Irradiation is also indicated for patients with rectal cancer at the first stage or as palliative treatment.