局部晚期肺癌三维适型放射治疗和调强放射治疗的剂量学比较研究

COMPARATIVE DOSIMETRY STUDY OF 3DCRT AND IMRT FOR TREATMENT OF LOCAL ADVANCED LUNG CANCER

目的观察和分析局部晚期非小细胞肺癌三维适型放射治疗和动态多叶准直器调强放射治疗在肿瘤靶区和剂量分布,比较两种治疗方法在剂量学上的优势性。方法入选2012年7月~2013年7月就诊于我院的未手术的IIIa期和IIIb期非小细胞肺癌患者52例,按随机抽样法分为两组各26例,分别给予三维适型放射治疗（Three Dimensional Conformal Radiation Therapy,3DCRT）和动态多叶准直器调强放射治疗（Intensity-modulated radiation therapy,IMRT）,根据CT分别勾画大体肿瘤体积（Gross Tumor Volume,GTV）、临床靶体积（Clinical Target Volume,CTV）、计划靶体积（Planning Target Volume,PTV）和危害气管,两种治疗方法剂量均为66Gy,标准为处方剂量至少覆盖95%的PTV,危害器官剂量均在耐受剂量范围内,通过靶区等剂量分布、适型指数和均数指数等对比肿瘤靶区剂量的差异。结果两组均能得到满足标准的剂量分布,两种治疗方法 PTV剂量比较提示平均剂量和最大剂量组间差异显著,p〈0.05,最小剂量组间差异无显著性,p〉0.05;CI和HI值组间差异显著,p〈0.05。结论 IMRT较3DCRT能够提高肿瘤靶区适型性,在保护正常组织器官上有显著优势,但均匀性下降。

Objective To observe and analyze the tumor target sections and dose distribution of 3DCRT and IMRT in the treatment of local advanced non- small cell lung cancer（ LANSCLC） and compare the advantages of the2 treatment methods on dosimetry. Methods 52 patients with IIIa and IIIb stage non- small cell lung cancer were given both 3DCRT and IMRT. GTV,CTV,PTV and harmed trachea were sketched by CT. Dose of both treatment methods was 66 Gy,and the criterion was that prescribed dose at least covered 95% PTV. Organ harmful doses were all within tolerable doses. Differences of tumor target section doses were compared according to dose distribution,conformity index and mean index of target section. Results Both groups got dose distributions satisfying criteria.PTV dose comparison of the 2 treatment methods showed that differences of mean dose and max dose group were significant（ P〈0. 05）,but between- group difference of min dose group was not significant（ P〉0. 05）. Differences of CI and HI values were significant（ P〈0. 05）. Conclusion IMRT and 3DCRT can improve tumor target formability,but reduce uniformity.