Definitive radical external beam radiotherapy for rectal cancer: Evaluation of local effectiveness and risk of late small bowel damage

Abstract

Aim. To present a retrospective analysis of results of definitive radiotherapy for rectal cancer. Material and methods. Forty-one consecutive patients with rectal cancer (32% primary, 61% pelvic recurrence and 7% after R2 resection) who could not be treated with surgery underwent external beam radiotherapy. A median tumour dose of 64 Gy was given with 1.8–2.5 Gy per fraction using 2D or 3D technique. In 46% of patients, concurrent 5-Fu-based chemotherapy was given. The median follow-up was 54 months. Results. Clinical complete response was achieved in 39% of patients. Five-year cumulative incidence of local failure, overall survival and cancer specific survival were 76%, 26% and 30%, respectively. Of 11 patients with local control, in five cases the tumour was larger than 5 cm and in the other five the tumour was fixed. Two patients, regarded as locally controlled had non-progressive tumour without local symptoms at the last follow-up of 54 and 118 months post-radiotherapy. Late toxicity occurred in 22% of patients, all with acceptable severity. There was no bowel obstruction requiring surgery despite that in 18 patients the small bowel dose was > 60 Gy to a mean volume of 51 cm³. Conclusion. Definitive radio(chemo)therapy provides a chance for local control even in patients with large fixed or recurrent rectal cancer.