目的:分析、比较用于治疗非小细胞肺癌(NSCLC)的基于Helical TomoTherapy (HT)和常规加速器的调强放疗(IMRT)计划靶区剂量均匀性、适形度以及危及器官受照体积和剂量分布方面的差异,为HT技术进一步深入运用于临床工作提供了参考数据.方法:回顾性随机选择10例NSCLC患者,分别采用HT加速器和常规加速器对每例NSCLC患者行IMRT计划设计,然后比较靶区及危及器官(OARs)的剂量体积参数的差异.结果:在靶区方面,HT IMRT计划的靶区剂量均匀性指数(HI)和适形度指数(CI)均优于常规加速器IMRT(P=0.035、P=0.000).在OARs方面,对于正常肺组织、V50、V30、V10、V5、平均剂量Dmean的差异有显著性意义(P=0.019、P=0.001、P=0.000、P=0.004、P=0.010).就V5、V10、Dmean而言,HT计划高于常规加速器计划,就V20、V30、V50而言,HT计划低于后者.食管V35、Dmean的差异有显著性意义(P=0.006、P=0.015),而食管V55、心脏、脊髓等危及器官的受量基本相同.结论:对于NSCLC,基于HT的调强放疗能够提高更好的靶区适形度和均匀性,正常肺组织低剂量区受照体积增大,在临床应用中应予以注意.%Objective: To compare HT and conventional linac-based intensity modulated radiotherapy (IMRT) for non-small cell lung cancer (NSCLC) in terms of homogeneity index, conformity index, dose and volume parameters of OARs. Methods: For a cohort of 10 patients, HT and Elekta precise linac-based 6MV IMRT planning was performed using identical planning objectives and dose constraints. Doses were computed with commercially available TPS using convolution/superposition (CS) algorithm. Plans were compared according to dose-volume histogram (DVH) analysis in terms of PTV homogeneity and conformity indices (HI and CI) as well as OARs dose and volume parameters. Results: Significant differences between HT and conventional linac-based plans were observed for HI and CI (P=0.035,P=0.000). For Dmean, V5， V10， V30， V50 of lung, significant difference existed between HT and Elekta precise-based IMRT (P=0.019 .P=0.001、P=0.000 、P=0.004 ,P=.010). Dmean V5 and V10 of HT were higher than those of the conventional linac while V20, V30 and V50 of HT were lower than those of the latter. For esophagus, V35, Dneanwere significantly different (P=0.006、P=0.015). The difference in high dose area for esophagus as well as heart and cord was not significant. Conclusions: For NSCLC, HT-based IMRT achieved better HI and CI. However, the irradiated volume of lung in low dose area increased which should arouse attentin in clinial work.
展开▼
