Second radiation may boost survival in returning throat cancer

This study is for people whose nasopharyngeal cancer has come back after initial treatment and cannot be removed by surgery. Participants first receive a combination of chemotherapy and an immunotherapy drug (PD-1 inhibitor). Those whose tumors shrink or disappear are then randomly assigned to receive either immediate re-irradiation or to wait and only get radiation if needed later. The goal is to see if adding radiation right away improves overall survival and delays cancer progression.