Phase II Study of Neoadjuvant Tislelizumab Plus Radiotherapy and GP Chemotherapy for Borderline/Unresectable Hilar Cholangiocarcinoma

SBRT to the primary tumor and metastatic lymph node at a dose of either 5 Gy × 5-8 fractions or 4 Gy × 15 fractions, delivered prior to systemic therapy.

Tislelizumab 200 mg administered intravenously every 3 weeks (on Day 1 of each 21-day cycle), for three to six cycles depending on surgical eligibility.

Gemcitabine 1000 mg/m² administered intravenously on Days 1 and 8 of each 21-day cycle, for three to six cycles.

Cisplatin 25 mg/m² on Days 1 and 8 or oxaliplatin 100 mg/m² on Day 1 of each 21-day cycle, selected based on patient condition, for three to six cycles.