放射治疗是恶性肿瘤最重要也是效价比最高的治疗手段之一，它可以改善患者营养摄入和营养状况，但是其不良 反应会导致营养不良的发生或营养状况的恶化。营养不良会对恶性肿瘤放疗患者造成不良影响，规范、有效的营养治疗具有 重要的意义，有利于保持患者体重，减少不良反应的发生，提高放疗的完成率和治疗疗效。放疗患者进行营养治疗的目的包 括：①诊断和治疗患者放疗前、中、后的营养不良；②减少患者不良反应的发生，增强放疗耐受性，减少放疗非计划性中断次数， 提高放疗完成率；③增加肿瘤细胞对放疗的敏感性，提高放疗精确度，提高患者的近远期疗效；④提高患者生活质量。

Radiotherapy is one of the most important and cost⁃effectiveness treatment for malignant tumors. Although it can improve the nutritional intake and status of patients, its adverse reactions may lead to the occurrence of malnutrition or the deterioration of nutritional status. Malnutrition will have adverse effects on patients with malignant tumor undergoing radiotherapy. Standardized and effective nutritional treatment is of great significance, which is conducive to maintaining the weight of patients, reducing the adverse reactions of radiotherapy, and improving the completion rate and therapeutic effect of radiotherapy. The purpose of nutritional therapy for radiotherapy patients includes: ① to diagnose and treat malnutrition before, during and after radiotherapy; ② to reduce the adverse reactions of radiotherapy, to enhance the radiotherapy tolerance, reduce the unplanned interruption of radiotherapy, and improve the radiotherapy completion rate; ③ to increase the sensitivity of tumor cells to radiotherapy, improve the accuracy of radiotherapy, and improve the short⁃term and long⁃term efficacy of patients; ④ to improve the quality of life of patients.