This is a multi-center, non-inferiority, open-label, randomized controlled phase III clinical trial in primary diagnosed nasopharyngeal carcinoma (NPC) patients without distant metastasis. The purpose of this study is to evaluate the efficacy of reduced neck prophylactic radiotherapy versus conventional neck prophylactic radiotherapy, and compare the radiotherapy-related adverse events and quality of life in two groups.

Inclusion Criteria:

• Newly histologic diagnosis of nasopharyngeal non-keratinizing carcinoma (WHO II/III);
• All genders, range from 18-70 years old;
• ECOG score 0-1;
• Clinical stage I-IVa (AJCC/UICC 8th);
• Not received radiotherapy, chemotherapy and other anti-tumor treatment (including immunotherapy);
• No contraindications to chemotherapy or radiotherapy;
• Adequate organ function: white blood cell count ≥ 4×109/L, neutrophile granulocyte count ≥ 1.5×109/L, hemoglobin ≥ 9g/L, platelet count ≥ 100×109/L; alanine aminotransferase or aspartate aminotransferase < 2.5×upper limit of normal; blood urea nitrogen or creatinine ≤ 1.5×upper limit of normal or endogenous creatinine clearance ≥ 60ml/min (Cockcroft-Gault formula);
• Sign the consent form.

Exclusion Criteria:

• Neck lymph nodes exist skipping metastasis;
• Distant metastases;
• Keratinized squamous cell carcinoma or basal cell like squamous cell carcinoma;
• Have or are suffering from other malignant tumors;
• Participating in other clinical trials;
• Pregnancy or lactation;
• Have uncontrolled cardiovascular disease;
• Severe complication, eg, uncontrolled hypertension;
• Mental disorder;
• Drug or alcohol addition;
• Do not have full capacity for civil acts.