(S038) Patient Tolerability and Acute Toxicity of Intensity-Modulated Radiation Therapy for Treatment of Carcinomas of the Biliary Tract

Lior Z. Braunstein, MD, A.X. Zhu, Jennifer Wo, MD, M. Anuciewicz, B. Napolitano, J. Wolfgang, H.J. Mamon, MD, PhD, L. Blaszkowsky, MD, D.P. Ryan, MD, T.S. Hong, MD; Harvard Radiation Oncology Program; Division of Hematology and Oncology and Department of Radiation Oncology, Massachusetts General Hospital; Department of Radiation Oncology, Brigham and Women’s Hospital; Department of Radiation Oncology, Dana-Farber Cancer Institute

Purpose and Objectives: Chemoradiation for biliary tract cancers (BTCs) has been associated with substantial toxicities due to the large, irregular target volumes surrounded by critical normal tissues. The purpose of this study was to evaluate patient tolerability and acute toxicity of chemoradiation with intensity-modulated radiation therapy (IMRT) for BTCs.

Materials and Methods: Patients receiving chemoradiation with IMRT for resected or locally advanced BTCs between March 2006 and July 2010 were retrospectively evaluated on an institutional review board (IRB)-approved protocol. Patients received radiation therapy to 50.4 Gy with concurrent 5-FU or capecitabine. Toxicity was scored using Common Toxicity Criteria version 3.0 (CTC v3.0). Adverse events were defined as hospitalization, emergency department visits, and treatment breaks/inability to complete therapy. Dose-volume histogram (DVH) parameters for liver, small and large bowel, and stomach were collected. Correlation of toxicity with DVH parameters was estimated and tested using Kendall’s nonparametric correlation coefficient. Disease-specific outcomes were estimated using the Kaplan-Meier method.

Results: A total of 28 consecutive patients were identified. Median age was 62 years (range: 38–81 yr), including 17 male (61%) and 11 female (39%) patients. Twelve patients had gallbladder cancer (43%), 12 had cholangiocarcinoma (CCA) of the common bile duct (43%), 8 patients had intrahepatic CCA (29%), and 4 had perihilar CCA (14%). Twenty-four patients received adjuvant radiation therapy (86%), while four patients were treated with definitive intent (14%). Of the resected tumors, 10 patients had negative surgical margins (36%), 8 patients had close margins (< 1-mm margin) (29%), and 4 patients had grossly positive margins (22%). Thirty-six percent had positive nodes. Median follow-up was 36.7 months (range: 4.6–76.2 mo). Local control (LC), progression-free survival (PFS), and overall survival (OS) rates at 1 year were 90%, 56%, and 76%, respectively. Grade 3–4 toxicity occurred in only two patients (7%). Three patients (11%) required treatment breaks, three patients (11%) had ED visits, and four patients (14%) required hospitalization. One patient died of a postoperative arterio-enteric fistula (4%) during the first week of radiation. There were no cases of radiation-induced liver disease. Analysis of dosimetric data for normal tissue structures revealed no significant correlations with toxicity or adverse events.

Conclusions: In one of the largest cohorts of such biliary tract cancers reported to date, chemoradiation with IMRT was well tolerated with minimal acute treatment-related toxicities. Due to the small number of adverse events, we were unable to determine dosimetric correlation of toxicity with DVH parameters. These data suggest that future prospective studies may safely evaluate radiation dose escalation as a means of improving BTC outcomes.

Proceedings of the 96th Annual Meeting of the American Radium Society - americanradiumsociety.org