Under Whole-course of Immunotherapy, Gradient Fractionated RT with CCT Versus CFRT with CCT for LANPC Who Achieved PR Post Induction Chemotherapy.

This prospective trial aims to enroll patients with stage III-IVA (AJCC 8th,) locoregionally advanced nasopharyngeal carcinoma (LANPC). Under the condition of full course of PD-1/PD-L1 blockades, patients who achieved radiological partial response after 3 cycles of platinum-based chemotherapy plus PD-1/PD-L1 blockades will be randomized in a 1:1 ratio to receive gradient radiotherapy (reducing the irradiation dose of PET-CT areas without metabolic abnormalities, while maintaining adequate irradiation dose of areas with metabolic abnormalities) or standard dose radiotherapy with concurrent chemotherapy. It is expected to provide a new therapeutic option for locally advanced nasopharyngeal carcinoma at moderate risk.