PD-1 Inhibitor Plus Chemotherapy Followed by Immediate Versus Selective Re-irradiation for Locally Advanced Recurrent NPC

This study is comparing two approaches for treating locally recurrent nasopharyngeal cancer (cancer at the back of the nose/throat that has come back): giving re-irradiation immediately after chemotherapy plus immunotherapy, versus giving re-irradiation only when disease progresses further. The goal is to find the best timing for re-treatment. **You may be eligible if...** - You are between 18 and 70 years old - Your nasopharyngeal cancer has come back locally more than one year after your original treatment - Your cancer responded (fully or partially) to 4–6 cycles of chemotherapy plus a PD-1 inhibitor - You have not received any treatment for the recurrence before enrolling - Your blood counts and organ function meet the required thresholds **You may NOT be eligible if...** - Surgery is an option for you - You have already received treatment for the recurrent cancer - You have conditions that would prevent you from receiving immunotherapy, chemotherapy, or radiation - Your performance level or organ function does not meet study requirements Talk to your doctor to see if this trial is right for you.