Hyperfractionated accelerated reirradiation for rectal cancer: An analysis of outcomes and toxicity

Background and purpose: To evaluate outcomes and toxicity in patients treated with hyperfractionated pelvic reirradiation for recurrent rectal cancer. Materials and methods: 102 patients with recurrent rectal adenocarcinoma were treated with pelvic reirradiation with a hyperfractionated accelerated approach, consisting of 1.5 Gy twice daily fractions to a total dose Of 30-45 Gy (median 39 Gy), with the most common total dose 39 Gy (n = 90, 88%). The median dose of prior pelvic radiation therapy (RT) was 50.4.Gy (range: 25-63 Gy). Results: The median follow-up was 40 months for living patients (range, 3-150 months). The 3-year freedom from local progression (FFLP) rate was 40% and the 3-year overall survival (OS) rate was 39%. Treatment with surgery was significantly associated with improved FFLP and OS, with 3-year FFLP rate of 49% vs. 30% (P = 0.013), and 3-year OS rate of 62% vs. 20% (P < 0.0001), compared to those without surgery. The actuarial 3-year rate of grade 3-4 late toxicity was 34%; patients who underwent surgery had a significantly higher rate of grade 3-4 late toxicity compared to those without surgery (54% vs. 16%, P = 0.001). Conclusions: This large, retrospective, single-institution study shows that hyperfractionated accelerated reirradiation was well tolerated. The rate of FFLP was promising, given that the study comprised heavily pre-treated patients with recurrences. Rates of FFLP and OS were particularly impressive in patients who underwent both reirradiation and surgery. Published by Elsevier Ireland Ltd.