Adaptive Immunotherapy for Nasopharyngeal Carcinoma

Inclusion Criteria: * 18-65 years; * Newly diagnosed, pathologically confirmed non-keratinizing carcinoma (according to WHO criteria); * Locoregionally advanced nasopharyngeal carcinoma (Stage II-III) as defined by the 9th edition of the American Joint Committee on Cancer (AJCC) staging system; * ECOG performance status: 0-1; * Adequate bone marrow function: white blood cell count \> 4 × 10⁹/L, hemoglobin \> 90 g/L, platelet count \> 100 × 10⁹/L; * Normal renal and hepatic function: total bilirubin ≤ 1.5 × upper limit of normal (ULN); aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) ≤ 2.5 × ULN; alkaline phosphatase ≤ 2.5 × ULN; creatinine clearance ≥ 60 mL/min; * Normal thyroid function, amylase, lipase, pituitary function; * Completion of 3 cycles of GP regimen induction chemotherapy combined with PD-1 inhibitor immunotherapy; * Patients must provide signed informed consent and be willing and able to comply with scheduled visits, treatment plans, laboratory tests, and other study procedures; * Female participants of childbearing potential must agree to use reliable contraceptive methods (e.g., condoms, regular use of oral contraceptives as prescribed) from screening until one year after treatment. Exclusion Criteria: * T3N0-1, according to the American Joint Committee on Cancer (AJCC) Staging System, 9th Edition; * Disease progression after induction therapy; * Hepatitis B surface antigen (HBsAg) positive with HBV DNA \>1×10³ copies/mL, or anti-hepatitis C virus (HCV) antibody positive; * Anti-HIV antibody positive or diagnosed with acquired immunodeficiency syndrome (AIDS); * Active tuberculosis; * Active, known, or suspected autoimmune disease. Exceptions include type 1 diabetes, hypothyroidism requiring hormone replacement therapy, and skin disorders not requiring systemic treatment (e.g., vitiligo, psoriasis, or alopecia); * History of interstitial lung disease or pneumonia requiring oral or intravenous steroid treatment within the past year; * Chronic systemic glucocorticoid therapy or any other form of immunosuppressive therapy. Subjects using inhaled or topical corticosteroids are eligible; * Uncontrolled cardiac disease; * Pregnant or lactating women; * History or current diagnosis of another malignancy, except for adequately treated non-melanoma skin cancer, carcinoma in situ of the cervix, or papillary thyroid carcinoma; * Known allergy to macromolecular protein preparations or any component of toripalimab; * Active infection requiring systemic treatment within one week prior to enrollment; * Administration of a live vaccine within 30 days before the first dose of toripalimab; * History of organ transplantation; * Contraindications to MRI examination, which would prevent the completion of required imaging; * Any other condition deemed by the investigators to potentially compromise patient safety or compliance.