A Prospective Randomized Controlled Study of Immune Checkpoint Maintenance Therapy After Radiotherapy and Chemotherapy for Locally Advanced Head and Neck Tumors Based on Peripheral Blood CD8Tex Detection in Peripheral Blood

This study is testing whether giving immune checkpoint therapy (a type of immunotherapy) after completing chemoradiation helps people with locally advanced head and neck tumors. Researchers are using a blood test that measures exhausted immune cells (CD8Tex) to identify which patients are most likely to benefit from ongoing immunotherapy after their initial treatment. **You may be eligible if...** - You are between 18 and 75 years old - You have been diagnosed with inoperable locally advanced head and neck cancer (stage T3 or higher, or involving lymph nodes) - You are undergoing or have completed concurrent chemoradiotherapy - Your general health status is good (ECOG 0–1) - Your blood counts, kidney, and liver function meet the required levels **You may NOT be eligible if...** - You have not completed chemoradiotherapy - Your organ function does not meet the study requirements - You are pregnant - Your performance status is poor Talk to your doctor to see if this trial is right for you.