SBRT Followed by Neoadjuvant Chemoimmunotherapy of Sindilizumab Plus Docetaxel and Cisplatin for Locoregionally Advanced Squamous Carcinoma of Oral Cavity and Oropharynx

This trial is testing a combination treatment for locally advanced mouth and throat (oral cavity and oropharyngeal) squamous cell cancers. The approach combines stereotactic body radiation therapy (SBRT), an immunotherapy drug (sintilimab), and two chemotherapy drugs (docetaxel and cisplatin) given before surgery, to shrink the tumor and improve surgical outcomes. **You may be eligible if...** - You are aged 18–70 with a pathologically confirmed squamous cell carcinoma of the oral cavity or oropharynx - Your cancer is locally advanced (Stage III–IVa per AJCC 8th edition) - You have no other organ dysfunction and are in adequate overall health (ECOG 0–1) **You may NOT be eligible if...** - You have another active cancer - You have autoimmune disease or a serious mental illness - You are at high risk of bleeding - You have received prior anti-PD-1/PD-L1 immunotherapy - You have active HIV, hepatitis C, or high-level hepatitis B infection - You used systemic steroids in the past 4 weeks Talk to your doctor to see if this trial is right for you.