PD-1 Inhibitor Therapy Versus Radiotherapy in pCR Patients With Locally Advanced HNSCC After Neoadjuvant Immunochemotherapy

In patients with locally advanced head and neck squamous cell carcinoma undergoing standard surgical treatment after neoadjuvant immunochemotherapy, can PD-1 inhibitor therapy be used instead of adjuvant radiotherapy for both primary and lymph node pathology? To provide further evidence-based medical evidence for the late precision treatment of HNSCC patients after neoadjuvant immunochemotherapy. Avoid the side effects caused by excessive radiotherapy, especially avoid the occurrence of second primary cancer, radiation osteonecrosis and other diseases. 1. Main study endpoint: A randomized controlled, non-inferiority, multicentre Phase III trial was conducted to investigate the difference in 5-year overall survival (OS) between experimental group (Group B) and control group (group A) in patients undergoing standard surgical treatment after neoadjuvant immunochemotherapy for locally advanced HNSCC, with both primary and lymph node pathology revealed by pCR. At the same time, adverse events and safety were evaluated according to NCI-CTCAE 5.0 criteria and RTOG later radiotherapy damage evaluation criteria. Safety indicators focused on late radiotherapy toxicity and the incidence of grade 3 and 4 adverse reactions in NCI-CTC AE 5.0 and RTOG. The differences in the incidence of grade 3 and 4 adverse events were compared between the experimental group and the control group. 2. Secondary study endpoint: The differences in 2-year disease-free survival (DFS), regional relapse-free survival (RRFS), distant metastasis free survival (DMFS), safety and adverse events were compared. Safety evaluation NCI-CTC AE 5.0 standard was used to evaluate the acute safety index of radiotherapy, and RTOG late-stage damage evaluation standard was used to evaluate the late-stage safety index of radiotherapy. 4\) Exploratory goals The influence of prognostic laboratory indicators, clinical risk factors were analyzed. To explore the factors that influence the efficacy of radiotherapy after pCR immunotherapy.