Application of Whole-course Standardized Nutrition Management During Peri-radiotherapy in Patients With Nasopharyngeal Carcinoma After Radiotherapy: a Multicenter Randomized Controlled Clinical Study

Inclusion Criteria: * Patients with nasopharyngeal carcinoma confirmed by histopathology * Newly diagnosed patients without distant metastasis * Age \>18 * KPS ≥ 70 * Nasopharyngeal radiotherapy alone or concurrent chemoradiotherapy was planned to be received, andIMRT was used for radiotherapy * The patient's blood counts，the lung, liver and renal functions were tolerant to radiotherapy/chemoradiotherapy（ WBC ≥ 4.0\*109/L, NE ≥ 2.0\*109/L, PLT 100\*109/L and Hb≥ 10g/L. AST and ALT ≤ 2.5 \*the upper limit（UL） ,TBIL≤1.2\*the UL, CRE≤1.2\* the UL, and ALP≤5\* the UL）. And the ECG should be normal * Good nutritional status,BMI:18\~23Kg/ m2, PG-SGA ≤1,NRS 2002\<3score * No other previous neoplastic diseases, except for cured cervical carcinoma in situ skin basal carcinoma * No serious gastrointestinal diseases (moderate and severe duodenal and gastric ulcer, ulcerative colitis, Crohn's disease, etc.) * No AIDS and no diabetes * Clear mind, no communication barriers, able to answer questions * Voluntarily participate and sign the informed consent in person. Exclusion Criteria: * Patients with gastrointestinal dysfunction, intestinal obstruction, pyloric obstruction, Acute gastrointestinal bleeding * Patients who are allergic to nutritional therapy or have severe allergic constitution * Uncontrolled systemic diseases, such as severe liver disease (such as cirrhosis), kidney disease, respiratory diseases and so on. * Women who are pregnant or breastfeeding or no contraception and women with positive pregnancy test before receiving treatment * Special dietary requirements: such as no having a certain food or a vegetarian.