The role of EUS-guided iodine-125 seed implantation in patients with unresectable cancer after relief of obstructive jaundice

Purpose: Few studies have focused on the management of inoperable ampullary carcinoma (AC), and patients with jaundice suffer from biliary stents replacement frequently. Iodine-125 (I-125) brachytherapy has been used in the treatment of malignant tumors owing to its curative effect, minimal surgical trauma, and tolerable complications. The aim of the study was to investigate the role of I-125 seed implantation in patients with unresectable ampullary carcinoma after relief of obstructive jaundice. Material and methods: A total of 44 patients with obstructive jaundice resulting from unresectable ampullary carcinoma from January 1, 2010 to October 31, 2020 were enrolled in the study. Eleven patients underwent implantation of I-125 seeds under endoscopic ultrasound (EUS) after receiving biliary stent placement via endoscopic retrograde cholangiopancreatography (ERCP) (treatment group), and 33 patients received a stent alone via ERCP (control group). Cox regression model was applied in this single-center retrospective comparison study. Results: The median maximum intervention interval for biliary obstruction was 381 days (interquartile range [IQR]: 204-419 days) in the treatment group and 175 days (IQR: 126-274 days) in the control group (p < 0.05). Stent occlusion rates at 90 and 180 days in the control group were 12.9% and 51.6%, respectively. No stent occlusion occurred in the treatment group. Patients in the treatment group obtained longer survival time (median, 26 vs. 13 months; p < 0.01) and prolonged duodenal obstruction (median, 20.5 vs. 11 months; p < 0.05). No brachytherapy-related grade 3 or 4 adverse events were observed. Conclusions: Longer intervention interval for biliary obstruction and survival as well as better stent patency and prolonged time to duodenal obstruction could be achieved by implanting I-125 seeds combined with biliary stent in patients with unresectable ampullary cancer.