Investigation of Multi-omics Technique to Predict the Efficacy of Chemoradiotherapy Combined With Immunotherapy for r/m NPC

Chemotherapy:cisplatin-based chemotherapy GP/TP/PF/TPF Choice of chemotherapy regimen is decided by patient's doctor in charge. Radiation: Intensity Modulated Radiation Therapy All target volumes will be outlined slice by slice on the axial contrast-enhanced CT with MR fusion images in the treatment planning system. The target volumes are defined in accordance with the International Commission on Radiation Units and Measurements Reports 83. The prescribed dose is 70-72 Gy to PTVp (Planning target volume of the primary tumor), 64-70 Gy to PTVn (Planning target volume of the lymph node),60- 64Gy to PTV1 (High-risk planning target volume), and 54-58 Gy to PTV2 (Low-risk planning target volume) in 30-32 fractions. The details of dose limits for organs at risk are based on the study 0225 from The Radiation Therapy Oncology Group (RTOG 0225). Immunotherapy:PD-1 blocking antibody