Patients with unresectable biliary tract cancer (intrahepatic or extrahepatic cholangiocarcinoma, or ampullary carcinoma) were enrolled and placed with a stent loaded with radioactive seeds (irradiation stent group) or a conventional plastic stent (traditional stent group). After stent placement, the outcomes were compared in terms of tumor response, progression-free survival, overall survival time, and complications related to the procedures.