Compare Radiotherapy Plus Nimotuzumab Versus Radiotherapy Alone in Platinum-ineligible Patients With Locoregionally Advanced Head and Neck Squamous Cell Carcinoma

Inclusion Criteria: * Eligible subjects must meet all of the following: * Age ≥18 years. * Histologically confirmed stage III-IVB (AJCC 8th edition) head and neck squamous cell carcinoma (including cancers of the oral cavity, oropharynx, hypopharynx, and larynx). * Unsuitable for surgical treatment (defined as: due to patient condition or tumor factors \[T3-4 N0-3 M0, or T1-2 N2-3 M0\] or medical reasons, surgery is not feasible; or an R0 resection is not achievable). * Suitable for definitive radiotherapy with curative intent. * At least one of the following reasons for being unsuitable for cisplatin-based chemotherapy: * Age ≥65 years and, in the investigator's judgment, unable to tolerate chemotherapy; * ECOG Performance Status \>2 (if this criterion is met, the ECOG criterion listed below may be waived); * Renal dysfunction: creatinine clearance (CrCl) \<50 mL/min (Cockcroft-Gault) (if this criterion is met, the renal function criterion listed below may be waived); * Severe tinnitus or hearing loss (requires a hearing aid or audiometry shows ≥25 dB loss at two consecutive frequencies); * Peripheral neuropathy \> Grade 1; * Inability to receive intravenous hydration (e.g., due to cardiac dysfunction) or other comorbidities, per investigator's judgment. * Provide tumor tissue, whenever possible, for EGFR testing; for oropharyngeal cancer, provide tissue for HPV/p16 testing if feasible (no need to retest if previously tested). * ECOG Performance Status 0-1 (…