非小细胞肺癌SBRT放疗剂量分布的研究

Dose distribution research of SBRT for non-small cell lung cancer

目的分别设计IMRT、VMAT和非共面VMAT三种放疗计划进行对比,以指导临床选择更优的SBRT治疗非小细胞肺癌(NSCLC)。方法 20例NSCLC患者,采用4D-CT定位获取定位图像,分别采用逆向调强(IMRT)、容积旋转调强(VMAT)和非共面容积旋转调强(N-VMAT)进行SBRT治疗计划的设计,比较计划靶区(PTV)和危及器官(OAR)的剂量分布图、剂量体积直方图(DVH)和机器的相关参数。结果对于靶区PTV的D_(2%)、D_(95%)、D_(50%)三种计划之间比较差异没有统计学意义(P>0.05)。靶区PTV的适形指数(CI),N-VMAT计划在剂量学的分布上整体优于IMRT计划和VMAT计划(P<0.05)。对于左肺的V_(5%)、V_(10%)、Dmean和右肺的V_(5%)、Dmean,N-VMAT计划在剂量学的分布上优于IMRT计划和VMAT计划(P<0.05)。结论 N-VMAT计划在剂量学的分布上整体优于IMRT计划和VMAT计划,它不仅有较好的靶区适形度和均匀度,而且有利于对肺组织的保护,可以为NSCLC患者的SBRT治疗提供理论参考。

Objective To guide a better clinical selection of SBRT plan in the treatment of non-small-cell lung cancer by comparing the plan of IMRT,VMAT and non-co-face VMAT.Methods The 20 NSCLC patients’positioning images was obtained by 4D-CT technique,and adopt Intensity Modulated Radiation Therapy(IMRT),Volumetric Modulated Arc Therapy(VMAT)and non coplanar Volumetric Modulated Arc Therapy(VMAT)to design SBRT treatment plan,then comparing the dose distribution,dose volume histogram(DVH)and the related parameters of plan target volum(PTV),organs at risk(OAR)and parameters of the machine.Results For D2%,D95%and D50%of PTV,there was no statistically significant difference between three plans(P>0.05).The conformal index(CI)of PTV were superior to the IMRT plan and VMAT plan(P<0.05).For V5%,V10%,Dmean of the right lung and V5%,Dmean of the left lung,the N-VMAT plan is better than the IMRT plan and the VMAT plan in the distribution of dosimetry(P<0.05).Conclusion N-VMAT plan as a whole is better than that of IMRT plan and VMAT plan.It not only has a good conformal target,but also has a lower illuminating dose for normal lung.It provides theoretical reference for SBRT treatment of NSCLC patients.