0引言肺癌发病时病期相对较晚,放射治疗是主要治疗手段之一。肺癌患者在接受分次放疗的过程中,放疗部位的位置和形状可能发生变化,体内的靶区与周围危及器官的位置关系也会发生变化,可能导致肿瘤靶区偏离射野,发生肿瘤的低剂量和危及器官的高剂量照射从而影响治疗效果。为了保 0 Introduction Lung cancer onset period is relatively late, radiation therapy is one of the main treatment. The location and shape of the radiotherapy site may change during lung cancer receiving fractionated radiotherapy. The target location in the body may also change with the location of the endangered organ in the surrounding area, which may lead to the deviation of the tumor target area from the radiation field and the occurrence of tumor low Dose and endanger the organs of high doses of radiation and thus affect the treatment effect. To protect