Image-guided intensity-modulated radiotherapy (IG-IMRT) for biliary adenocarcinomas: Initial clinical results.

Abstract

Biliary tract lesions are comparatively rare neoplasms, with ambiguous indications for radiotherapy. The specific aim of this study was to report the clinical results of a single-institution biliary tract series treated with modern radiotherapeutic techniques, and detail results using both conventional and image-guided intensity-modulated radiation therapy (IG-IMRT). From 2001 to 2005, 24 patients with primary adenocarcinoma of the biliary tract (gallbladder and extrahepatic bile ducts) were treated by IG-IMRT. To compare outcomes, data from a sequential series of 24 patients treated between 1995 and 2005 with conventional radiotherapy (CRT) techniques were collected as a comparator set. Demographic and treatment parameters were collected. Endpoints analyzed included treatment-related acute toxicity and survival. Median estimated survival for all patients completing treatment was 13.9 months. A statistically significant higher mean dose was given to patients receiving IG-IMRT compared to CRT, 59 vs. 48Gy. IG-IMRT and CRT cohorts had a median survival of 17.6 and 9.0 months, respectively. Surgical resection was associated with improved survival. Two patients (4%) experienced an RTOG acute toxicity score>2. The most commonly reported GI toxicities (RTOG Grade 2) were nausea or diarrhea requiring oral medication, experienced by 46% of patients. This series presents the first clinical outcomes of biliary tract cancers treated with IG-IMRT. In comparison to a cohort of patients treated by conventional radiation techniques, IG-IMRT was feasible for biliary tract tumors, warranting further investigation in prospective clinical trials.