Induction Chemoimmunotherapy Followed by Deescalated Definitive Radiotherapy in Head and Neck Cancer

This study aims to evaluate whether reducing the intensity of radiotherapy (de-escalated radiotherapy) after induction chemoimmunotherapy is not inferior to standard-dose radiotherapy in patients with locally advanced head and neck squamous cell carcinoma (HNSCC). The study is a multicenter, prospective, phase II, randomized, non-inferiority controlled trial. A total of 180 participants who achieve deep tumor response (≥50% regression) after 2-3 cycles of induction chemotherapy plus PD-1 inhibitor (camrelizumab) will be randomized 1:1 to receive either de-escalated radiotherapy (experimental group) or standard radiotherapy (control group). Additional maintenance camrelizumab for 8 cycles after radiotherapy will be administered for both groups. The primary outcome is 2-year progression-free survival (PFS). Secondary outcomes include overall survival, local-regional control, distant metastasis-free survival, treatment-related adverse events, and quality of life. The study is expected to start in June 2026 and complete in December 2031.