Adaptive Immunotherapy for Nasopharyngeal Carcinoma

1. To assess whether radiotherapy alone is non-inferior to concurrent chemoradiotherapy with respect to event-free survival and superior in reducing treatment-related nausea in low-risk locoregionally advanced nasopharyngeal carcinoma patients who achieve complete or partial response and undetectable serum EBV-DNA following induction chemoimmunotherapy. 2. To evaluate whether adjuvant capecitabine and immunotherapy after concurrent chemoradiotherapy improves event-free survival compared to adjuvant immunotherapy in high-risk locoregionally advanced nasopharyngeal carcinoma patients with stable disease or detectable serum EBV-DNA after induction chemoimmunotherapy.