所有恶性肿瘤放疗患者均应进行营养不良三级诊断，包括营养筛查、营养评估和综合测定。营养风险筛查推荐 采用NRS 2002 量表，营养评估推荐采用PG-SGA 量表。不推荐对恶性肿瘤放疗患者常规进行营养治疗。临床医师应该综 合评估患者的营养状况（PG-SGA评分）及放疗过程中急性放射损伤（RTOG 分级），筛选出具备营养治疗适应证的患者， 选择合理的营养治疗路径，及时给予营养治疗。恶性肿瘤放疗患者的营养治疗采用五阶梯治疗原则，肠内营养途径的选择 采用四阶梯原则。不推荐放疗前预防性置入营养管，除非患者存在以下一种或多种情况：明显体重丢失（1 个月内大于5% 或者6 个月内大于10%）、BMI 小于18.5、严重吞咽梗阻或疼痛、严重厌食、脱水、预期将发生严重放射性口腔或食道黏 膜炎。恶性肿瘤放疗患者能量摄入推荐量为25~30kcal/(kg·d)，但应在放疗过程中根据肿瘤负荷、应激状态和急性放射损伤 动态调整。恶性肿瘤放疗患者应该减少碳水化合物在总能量中的供能比例，提高蛋白质、脂肪的供能比例。谷氨酰胺对 降低放射性皮肤毒性、放射性黏膜炎的发生率和严重程度有益处，ω-3 PUFA 有利于提高放疗患者免疫功能，调节机体炎性 反应，建议在肠内营养配方中加入。在恶性肿瘤放疗患者肠内营养过程中，医师应该根据不同观察指标的反应快慢对肠内 营养的疗效和不良反应进行定期评价。患者出院后，如果仍存在经口摄入营养不足或营养管依赖的情况，应该给予家庭肠 内营养治疗和管理。

All the cancer patients receiving radiotherapy should routinely undergo three-stage diagnosis of malnutrition after cancer diagnosis or admission to the hospital. The three-stage diagnosis of malnutrition includes nutritional screening, nutritional assessment and comprehensive measurement. NRS-2002 is recommended for nutritional risk screening, and PG-SGA is recommended for nutritional assessment. Conventional nutritional therapy is not recommended for cancer patients. We should correctly assess the nutritional status of patients using PG-SGA and acute radiation injury during radiotherapy according to RTOG criteria. According to the results of the comprehensive evaluation, patients who are malnutrition or at risk of malnutrition will receive nutrition therapy in time on the basis of the treatment path. The five-step nutrition treatment principle is also adopted for the radiotherapy cancer patients, and the four-step principle is adopted for the choosing of enteral nutrition pathway. Prophylactic implantation of nutrient tube before radiotherapy is not recommended unless the patients has one or more of the following situations: significant weight loss (greater than 5% within one month or greater than 10% within six months), BMI less than 18.5, severe dysphagia or painful swallowing, severe anorexia, dehydration, and prospective severe radiation-induced oral or esophageal mucositis. The recommended amount of energy intake for radiotherapy patients with malignant tumor is 25~30kcal/(kg·d). It should be adjusted dynamically according to tumor burden, stress state and acute radiation injury during radiotherapy. We should reduce the proportion of carbohydrates and increase the proportion of protein and fat supply in the total energy supply. Glutamine is beneficial in reducing the incidence of radioactive skin toxicity and severity of radiation mucositis. Omega-3 PUFA is beneficial for improving immune function and regulating inflammatory response in patients undergoing radiotherapy. It is recommended that glutamine and Omega -3 PUFA be added to the enteral nutrition formula. Doctors should evaluate the efficacy and adverse reactions of enteral nutrition according to the reaction speed of different observation indexes during radiotherapy. Radiotherapy patients with malignancies who are out of hospital should be given home enteral nutritional support and management if they are still suffering from inadequate intake of nutrients through mouth, or who have the nutrient tube dependence.