Many patients with rectal cancer receive radiotherapy as a component of primary multimodality treatment. Although local recurrence is infrequent, reirradiation may be needed to improve resectability and outcomes. This systematic review investigated the effects of reirradiation in terms of feasibility, toxicity, and long-term outcomes.

A Medline, Embase and Cochrane search resulted in 353 titles/abstracts. Ten publications describing seven prospective or retrospective studies were included, presenting results of 375 patients reirradiated for rectal cancer.

Median initial radiation dose was 50.4Gy, median 8-30months before reirradiation. Reirradiation was mostly administered using hyperfractionated (1.2-1.5Gy twice-daily) or 1.8Gy once-daily chemoradiotherapy. Median total dose was 30-40Gy to the gross tumour volume with 2-4cm margins. Median survival was 39-60months in resected patients and 12-16months in palliative patients. Good symptomatic relief was reported in 82-100%. Acute toxicity with diarrhoea was reported in 9-20%, late toxicity was insufficiently reported.

Reirradiation of rectal cancer to limited volumes is feasible. When curative resection is possible, the goal is radical resection and long-term survival, and hyperfractionated chemoradiotherapy should be preferred to limit late toxicity. Reirradiation yielded good symptomatic relief in palliative treatment.