[Cancer of the rectum: current trends in radiotherapy in conservative treatment]

Conservative treatment of rectal cancer by intracavitary irradiation (Philips contact x-ray therapy followed or not by Iridium implant) is only applicable to tumours which are thought to have no lymphatic spread. A strict selection of cases is compulsory, especially with regard to the probability of lymph node involvement (degree of histological differentiation, degree of infiltration of the rectal wall, absence of palpable pararectal metastatic lymph nodes). After treatment, follow-up must be performed methodically. Moreover, in patients not older than 55, mesenteric and perirectal lymphadenectomy must be considered. At the Centre Léon Bérard (Lyon), 231 patients followed more than 5 years have been treated. The 5-year and 10-year survival rates are respectively 57 per cent and 74 per cent. The rate of local failure is 5.2 per cent. The rate of death from cancer at 5 and 10 years is 10 per cent. However intracavitary irradiation is only applicable in 10 to 15 per cent of rectal cancers. A new conservative approach has been worked out. It consists of preoperative external beam irradiation with Cobalt 60 (30 Gy in 12 days) followed 2 months later, according to the residual disease, either by radical surgery of Iridium implant. Applied to poor risk, patients this method can spare many of a permanent colostomy, without jeopardizing their chances of cure (27 cases, median age: 77 years).