Prophylactic Radiotherapy Optimization for Enhanced Thyroid Function Protection in NPC

Prophylactic Radiotherapy Optimization for Enhanced Thyroid Function Protection in Nasopharyngeal Carcinoma (PROTECT-NPC): A Multicenter, Non-Inferiority, Open-Label, Randomized Controlled Phase III Clinical Trial

This study is a multicenter, non-inferiority, open-label, randomized controlled Phase III clinical trial. It aims to compare the efficacy of modified delineation radiotherapy (experimental group) versus standard delineation radiotherapy (control group) in the prophylactic irradiation of neck lymphatic drainage areas III/IVa in nasopharyngeal carcinoma. The study evaluates the incidence of primary hypothyroidism, quality of life, and adverse events between the two groups.

Inclusion Criteria:

1. Male or female, aged 18-70 years; 2. Pathologically confirmed nasopharyngeal carcinoma; 3. No positive lymph nodes in unilateral or bilateral regions III and IVa; 4. Clinical stage I-IVa (AJCC/UICC 8th edition), with no evidence of distant metastasis; 5. Normal thyroid function; 6. ECOG performance status of 0-1; 7. Treatment-naïve patients who have not received any prior antitumor therapy; 6. No contraindications to radiotherapy or chemotherapy; 9. Adequate organ function, meeting the following criteria: Hematologic criteria: WBC ≥ 4.0 × 10⁹/L, ANC ≥ 1.5 × 10⁹/L, PLT ≥ 100 × 10⁹/L, HGB ≥ 90 g/L (no transfusion, blood products, or hematopoietic growth factors used within the past 7 days); Biochemical criteria: ALT and AST < 1.5 × ULN, ALP < 2.5 × ULN, total bilirubin < ULN, BUN and creatinine ≤ 1.5 × ULN or creatinine clearance rate ≥ 60 mL/min (calculated using the Cockcroft-Gault formula).

10. Voluntarily agreed to participate in the study, signed the informed consent form, demonstrated good compliance, and agreed to follow-up.

Exclusion Criteria:

1. History of other malignant tumors (excluding basal cell carcinoma/squamous cell carcinoma of the skin or cervical carcinoma in situ);
2. History of radiotherapy (excluding radiotherapy outside the planned target area for conditions such as melanoma);
3. History of neck surgery;
4. Any severe comorbidities that may pose risks to the study or affect compliance, such as unstable heart disease requiring treatment, kidney disease, chronic hepatitis, poorly controlled diabetes (fasting blood glucose > 1.5 × ULN), or psychiatric disorders;
5. History of hyperthyroidism, hypothyroidism, or immune-related thyroid disorders;
6. Other family or social factors, as judged by the investigator, may force the study's early termination, compromise patient safety, or affect the collection of trial data.