Consolidative Radiotherapy (CSRT) in Patients With Oligometastatic/Locally Advanced Unresectable Bilary Tract Cancer (BTC)

Consolidative radiotherapy: total dose and number of fractions will depend on the site of disease. Treatment will be given daily, or every other day, over 1 -3 weeks. Physicians should try to give the highest BED whenever possible while respecting normal tissue tolerance. All lesions are recommended to receive a biologically effective dose (BED) of 60 Gy or higher (BED10≥70), assuming α/β ratio of 10 and using the linear-quadratic model: BED = nd x \[1 + d/(α/β)\] where n is number of fractions and d is dose per fraction. Sometimes BED ≥80 Gy is preferred, with lower doses ≥50 Gy allowed at the discretion of the treating physician for concerns about normal tissue toxicity.

Standard-of-care systemic therapy as decided by the treating medical oncologist: Gemcitabine + cisplatin/oxaliplatin + Durvalumab/Pembrolizumab/Sintilimab/Toripalimab