Effect of Nutritional Management on RIOM in Patients With Advanced Head and Neck Cancer

The goal of this clinical trial is to learn about the effect of nutritional management on radiation-induced oral mucositis in patients with advanced head and neck cancer during the peri-radiotherapy period . The main questions it aims to answer are: * \[question 1\]Whether whole-course nutritional intervention can improve radiation-induced oral mucositis in patients with HNC. * \[question 2\]Whether whole-course nutritional intervention can improve nutritional status and inflammation. Participants will be treated according to the NCCN guidelines. In addition, clinical pharmacists and registered dietitians provided nutritional intervention strategies based on clinical and nutritional assessments for the patients in the peri-radiotherapy nutrition group. Researchers will compare clinical routine examination and nutritional indicators between the standard treatment group and the peri-radiotherapy nutrition management group to see if nutrition management effects.