A systematic review of intraluminal high dose rate brachytherapy in the management of malignant biliary tract obstruction and cholangiocarcinoma

•Cholangiocarcinoma is the most common cause of malignant biliary tract obstruction.•HDR intraluminal brachytherapy (ILBT) resulted in longer duration of stent patency.•HDR ILBT resulted in improved survival with low rates of complication and toxicity.•Future studies should consider HDR ILBT with stenting prior to chemotherapy.•This approach may improve patient quality of life, and potentially prolong survival. To conduct a systematic review evaluating the impact of high dose rate (HDR) intraluminal brachytherapy (ILBT) in the management of malignant biliary obstruction and cholangiocarcinoma with specific focus on stent patency, clinical outcomes and toxicities. A review of published articles was conducted using Medline, Embase and Cochrane databases using the search terms “bile duct carcinoma” or “cholangiocarcinoma” or “bile duct neoplasms” in combination with “brachytherapy” or “high dose rate brachytherapy” or “HDR brachytherapy”. Studies published in English and reporting outcomes of ≥10 patients were included in the review. Only the most recent experience was included if same patients were included in sequential publications. Seventeen studies were identified that met the inclusion criteria. Significant heterogeneity was observed in treatment regimens, which included use of surgery, external beam radiation (EBRT), and/or intra-arterial and intravenous chemotherapy in conjunction with ILBT. Nevertheless, among the included studies, use of ILBT appeared to result in longer duration of stent patency: 10 months with ILBT compared to 4–6 months without ILBT. A trend was observed towards prolonged local control and improved complete and partial response rates in patients treated with ILBT with or without EBRT. Weighted mean overall survival of patients treated with ILBT alone was 11.8 months compared to 10.5 months for those that received EBRT +/− chemotherapy in addition to ILBT. The included studies reported low complication rates and toxicity related to ILBT. Brachytherapy can be an effective and safe tool in the management of malignant biliary tract obstruction in combination with stenting. Both retrospective and prospective studies have suggested improved outcomes when HDR ILBT is combined with percutaneous stenting.