The purpose of this randomized controlled study is to evaluate the efficacy and safety of the Radiation-Emitting Metallic Stents (REMS) combined with Trans-Arterial Infusion (TAI) for unresectable hilar cholangiocarcinoma.

This is a multicentric, open-labal, randomized controlled trial which aims to evaluate the efficacy and safety of Radiation-Emitting Metallic Stents (REMS) combined with Trans-Arterial Infusion (TAI) versus Uncovered Self-Expandable Metallic Stent (SEMS) Combined With Trans-Arterial Infusion (TAI) for Unresectable Hilar Cholangiocarcinoma. The primary hypotheses are that Radiation-Emitting Metallic Stents (REMS) combined with Trans-Arterial Infusion (TAI) is superior to Uncovered Self-Expandable Metallic Stent (SEMS) Combined With Trans-Arterial Infusion (TAI) with respect to Over survival(OS). The primary endpoint is overall survival. The secondary endpoints include quality of life, progression free survival, relief of jaundice, patency, and adverse events.

Inclusion Criteria:

• Clinically or histopathologically diagnosis of cholangiocarcinoma
• With symptoms such as jaundice related to biliary obstruction
• Biliary obstruction of Bismuth-Correlate Classification Type III or IV
• Unresectable disease confirmed by multidisciplinary team
• Maximum diameter of lesion ≤3 cm
• Liver function of Child-Pugh A or B
• 18 years older
• With an expected survival time ≥ 3 months
• With an Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2
• Meet the following laboratory test parameters: hematologic function (absolute neutrophil count ≥ 1.0×10⁹/L; platelet count ≥ 50×10⁹/L; hemoglobin ≥ 90 g/L; INR < 1.7 or prolonged prothrombin time not more than 4 seconds); liver function (ALT/AST not more than 5 times the upper limit of normal; albumin ≥ 28 g/L); renal function (serum creatinine not more than 1.5 times the upper limit of normal)

Exclusion Criteria:

• Presence of distant metastases
• With another malignancy type other than cholangiocarcinoma
• Previous history of biliary stent placement
• Moderate to severe ascites (ascites up to Child-Pugh score of 3)
• Biliary perforation
• History of abdominal fistula, gastrointestinal perforation, or intra-abdominal abscess within 4 weeks prior to enrollment
• Unstable angina, myocardial infarction, coronary artery bypass graft, congestive heart failure, cerebrovascular accident (including transient ischemic attack, pulmonary embolism) within 3 months before enrollment
• Persistent arrhythmia (CTCAE criteria grade 2 and above), atrial fibrillation of any degree, prolonged Qtc interval (more than 450 ms in men and more than 470 ms in women)
• Refractory hypertension (blood pressure above 150/100 mmHg even after optimal drug therapy
• Concomitant receipt of other anti-tumor drugs
• Concomitant human immunodeficiency virus (HIV) infection or acquired immunodeficiency syndrome
• Pregnant or lactating women
• Concomitant acute or chronic mental disorders (including mental disorders affecting subject enrollment, therapeutic intervention, and follow-up)