Induction High-Low Dose Radiotherapy Plus Anti-PD-1 Followed by Definitive Radiotherapy in Recurrent Nasopharyngeal Carcinoma (Single-Arm Phase II)

This trial is studying a new radiation approach — combining high and low doses of radiation with an immunotherapy drug — as a treatment for nasopharyngeal carcinoma (a cancer at the back of the nose) that has come back after previous radiation therapy. **You may be eligible if...** - Your nasopharyngeal cancer has come back locally at least 1 year after completing your first course of radiation - The cancer has not spread to distant organs - You are not a candidate for surgery - Your cancer is at a specific stage (rT2-rT4 by AJCC 8th edition) - You are in good physical condition (ECOG 0–1) - Your organ function is adequate **You may NOT be eligible if...** - Your cancer has spread to distant sites (e.g., lungs, liver, bones) - There is active tissue death (necrosis) at the recurrence site - You have an active autoimmune disease - You have previously been treated with PD-1 or PD-L1 immunotherapy - You have uncontrolled infections (including active hepatitis B/C or HIV) - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.