Purpose: The purpose of this study was to analyze the efficacy and acute and late toxicity of reirradiation for recurrent rectal cancer.
Methods and materials: Fifty-two patients with recurrent rectal adenocarcinoma following previous pelvic RT underwent reirradiation. Median initial RT dose to the pelvis was 50.4 Gy. Median reirradiation dose was 30.6 Gy. Twenty-two patients received 1.2 Gy b.i.d., and 30 patients received 1.8-2.0 Gy daily. Total cumulative doses ranged from 66.6 to 104.9 Gy (median: 84.4 Gy). Forty-seven patients (90%) received concurrent 5-FU chemotherapy. Forty-four patients were followed until death, and the median follow-up time was 16 months.
Results: The RTOG Grade 3 acute toxicity rate was 31%. The RTOG Grade 3 and 4 late toxicity rates were 23 and 10%, respectively. On multivariate analysis, the only factor associated with reduced late toxicity was hyperfractionated delivery of reirradiation. Bleeding, pain, and mass effect were palliated completely in 100, 65, and 24% of instances, respectively, and the majority of responding patients were palliated until death. The overall median survival time from retreatment was 12 months. The 2- and 3-year overall actuarial survival rates were 25 and 14%, respectively.
Conclusion: This unique institutional approach to recurrent rectal cancers resulted in excellent palliation of symptoms. Late complications appeared reduced by hyperfractionated treatment delivery.