The goal of this clinical trial is to determine the maximum tolerated dose and the recommended phase II dose for nab-paclitaxel when administered concurrently with radiotherapy in nasopharyngeal carcinoma. Researchers will observe the toxicity response of patients receiving nab-paclitaxel at 180 mg/m², 200 mg/m², 230 mg/m², and 260 mg/m².

Inclusion Criteria:

• Pathologically confirmed nasopharyngeal carcinoma
• III-IVa (AJCC8th)
• age 18-70
• PS score 0-1
• normal functions to tolerate chemotherapy and radiotherapy

Exclusion Criteria:

• The presence of other malignant neoplasms within the preceding five years, with the exception of carcinoma in situ, adequately treated non-melanoma skin cancer and papillary thyroid cancer, is permitted.
• Symptomatic heart failure, unstable angina, myocardial infarction, active infections requiring systemic therapy, psychiatric disorders, or family and social factors