Twenty-year experience in the management of squamous cell anal canal carcinoma with interstitial brachytherapy

Objectives The aim of this study was to retrospectively evaluate clinical characteristics, local control, acute and late toxicity, and prognostic factors of patients with anal canal carcinoma treated with brachytherapy. Methods From 1989 to 2009, 38 patients were treated with iridium 192 low-dose-rate (N=26) or pulsed-dose-rate (N=12) interstitial brachytherapy at a single institution. The median age was 62 years (range, 38–86 years). The TNM classification was as follows: 10 T1, 22 T2, 5 T3 and 1 T4; 32 N0, 3 N1 and 3 N2. Most patients (32/38) received either a first course of radiochemotherapy (N=22) or radiotherapy alone (N=10) consisting of a total delivered dose of 45 Gy to the pelvis (range, 32–50) followed by a boost a median of 18 days later of 15–35 Gy (median 20 Gy) to the anal canal. The remaining 6 cases were treated with brachytherapy alone (dose range, 60–65 Gy). Results With a median follow-up of 30 months (range, 4–200), 2- and 5-year local control rates were 91% and 87%, respectively. Preservation of the anal sphincter was achieved in 32 patients (84%). Three patients experienced incontinence after brachytherapy. Only 2 patients showed chronic mucositis grade 3/4. Age proved to be a statistically significant prognostic factor for overall survival in the univariate ( p =0.033) and multivariate analyses ( p =0.018). Concurrent chemotherapy with external beam radiotherapy was a statistically significant prognostic factor for disease-free survival in the univariate and multivariate analyses ( p =0.007 and p =0.044, respectively). Conclusions Interstitial brachytherapy appears to be an effective and well tolerated treatment for anal carcinoma offering both high local tumour control and anal sphincter preservation.