Proton vs Photon IMRT in Locally Advanced Nasopharyngeal Carcinoma: A Phase III Trial

Inclusion Criteria: * Age 18 to 70 years * Histologically confirmed nasopharyngeal carcinoma (WHO type II or III) * High-risk locoregionally advanced disease defined as clinical stage T4 or N3, M0, according to the AJCC staging system * No prior anti-tumor therapy for nasopharyngeal carcinoma, including radiotherapy, chemotherapy, targeted therapy, or immunotherapy * Eastern Cooperative Oncology Group (ECOG) performance status of 0-1 * Adequate organ function as defined in the study protocol * Eligible to receive induction chemotherapy followed by concurrent chemoradiotherapy combined with immunotherapy as specified in the protocol * Ability to understand and willingness to sign written informed consent Exclusion Criteria: * Evidence of distant metastasis (M1 disease) * Prior radiotherapy, chemotherapy, targeted therapy, or immunotherapy for nasopharyngeal carcinoma * Active autoimmune disease requiring systemic therapy * Uncontrolled infection or severe comorbidities that may affect treatment tolerance * Pregnancy or breastfeeding * Known allergy, hypersensitivity, or contraindication to study medications as defined in the protocol * Any other condition that, in the investigator's judgment, makes the patient unsuitable for participation