Radioactive needle implants in the treatment of anorectal cancer.

Radioactive needle implants were used to treat 44 patients with inoperable anorectal cancer. An implant dose of 60 Gy or higher was administered to 27 patients at a mean dose rate of 0.493 Gy/h (SE +/- 0.167 Gy/h). In five patients this was preceded by external beam irradiation. A further 17 patients received an implant dose of less than 60 Gy; this followed external irradiation in 10 patients. A complete response was achieved in 52% (16 out of 31) of patients assessed. Three of these patients later relapsed locally. The median duration of response was 23 months. A partial response of median duration 3 months was achieved by a further 13 patients. Five year actuarial survival was 23.9%. Serious morbidity occurred in six patients; three developed strictures and three necrosis. Features of the tumour and the treatment technique contributing to successful management are discussed. It is suggested that radioactive needle implants have an important part to play in the management of low-lying inoperable anorectal cancers.