This study is a single-center, double-blind, randomized controlled clinical trial with placebo as the control, aiming to evaluate the effectiveness of spermidine in preventing radiation-induced xerostomia during radiotherapy for head and neck tumors (including nasopharyngeal carcinoma).
Patients with histopathologically confirmed head and neck squamous cell carcinoma (including nasopharyngeal carcinoma).
Aged ≥18 years and ≤80 years.
ECOG performance status score ≤2.
Receiving radical radiotherapy or concurrent chemoradiotherapy with radiation dose >50 Gy, where: Both parotid glands receive an average dose ≥25 Gy; or one gland receives a dose ≥25 Gy and the other receives any dose.
History of xerostomia, Sjögren's syndrome, or other known systemic diseases predisposing to dry mouth.
Wheat allergy or gluten intolerance.
Suspected or confirmed physical occlusion of bilateral salivary gland ducts.
Prior history of head and neck radiotherapy.