Neoadjuvant SBRT in Localized Advanced HNSCC

Inclusion Criteria: 1. Pathologically confirmed initially resectable Localized advanced head and neck squamous cell carcinoma，and plan for surgical resection. 2. Immunohistochemical confirmed the HPV status through P16 immunostaining. 3. Male or female, Between the aged from 18 to 70 years, 4. Able to provide informed consent, comply with agreements, and sign research specific consent documents. 5. ZPS is less than 2. 6. Adequate bone marrow, liver and kidney, heart , lung and other physiological function determined by Researchers, able to tolerate neoadjuvant anti-PD-1, anti-EGFR, and radiation therapy. 7. Subjects are willing and able to comply with visits, treatment regimens, laboratory tests, and other requirements of the study as spe. Exclusion Criteria: 1. Any clinical illness, such as hemorrhage, active infection, or mental illness, that can hinder safe participation or adherence of research procedures. 2. Patients who cannot accept radiotherapy in standard treatment. 3. Long term maintenance of oral steroids (≥ 20mg prednisone equivalent per day) is required, excluding patients with inhaled, local, or non absorbable steroids. 4. Autoimmune diseases, including but not limited to inflammatory bowel disease, rheumatoid arthritis, autoimmune hepatitis, systemic sclerosis (scleroderma and variants), systemic lupus erythematosus, autoimmune vasculitis, autoimmune neuropathy (such as Guillain Barre syndrome), etc.