Interstitial Brachytherapy for the Treatment of Locally Recurrent Anorectal Cancer

Background: Local tumor control (LC), overall survival (OS), symptom palliation, and late toxicity for patients with locally recurrent anorectal cancer treated with a computed tomography (CT)-guided interstitial brachytherapy implant were examined. Methods: The medical records of 20 consecutive patients who had received interstitial brachytherapy for locally recurrent anorectal cancer from 2000 through 2012 were reviewed. Seventeen patients (85 %) had rectal cancer and three had anal cancer [median follow-up time for living patients, 23 months (range 13–132)]. Brachytherapy was used most commonly at the second pelvic recurrence (n = 13, 65 %). The implant dose was prescribed to 80 Gy to a 1-cm margin or 120 Gy to 100 % of the gross tumor volume. Endpoints were OS, LC, toxicity, and symptom palliation rate, all calculated from the time of implant. Results: The actuarial 1-year rates of LC and OS were 80 and 95 %, respectively. At presentation, 17 patients (85 %) had symptoms related to the treated tumor which were palliated in 13 patients (76 %) at a median time of 3 months (range 1–6); palliation was permanent for seven patients (54 %), and the other six patients lost palliation after a median 8 months (range 5–17). One patient experienced a grade 3 late complication requiring a stent for hydronephrosis; five had grade 2 toxicity, and four had grade 1 toxicity. Conclusions: CT-guided interstitial brachytherapy for locally recurrent anorectal tumors produced durable tumor control and long-term survival, with effective palliation and minimal long-term morbidity.