High dose reirradiation is usually recommended for unresectable recurrent loco-regionally advanced nasopharyngeal carcinoma. However, it potentially adds to the RT-related severe toxicities and deaths. This trial aims to investigate the feasibility of postponing or even omitting re-irradiation based on effective first-line systemic therapy with tislelizumab and chemotherapy. For patients that progressed after exposure to another PD-1 antibody,tislelizumab rechallenge is accepted as a second subgroup.In this trial, all patients will receive chemotherapy (on doctors' recommendation) and PD-1 antibody (tislelizumab 200mg every three weeks). Patients with no response to the systemic therapy will receive salvage low dose re-irradiation delivered by SBRT, while those who showed complete or partial response will continue maintenance therapy until progression, death or intolerable toxicity, and reirradiation will be postponed or omitted.
This is an open-label, multi-center, phase II trial to evaluate the safety and efficacy of postponing or omitting re-irradiation after systemic therapy with tislelizumab and chemotherapy in patients with unresectable recurrent loco-regionally advanced nasopharyngeal carcinoma. Patients who did not respond to or progressed on another ICI are allowed to receive tislelizumab rechallenge as a subgroup.