作　　者： ; ; ; ; ;

机构地区： 暨南大学

出　　处： 《中国医学物理学杂志》 2017年第7期719-725,752,共8页

摘　　要： 目的:比较高级别脑胶质瘤(HGG)术后采用不同拉弧数量容积旋转调强放疗(VMAT)和不同照射野数量逆向调强放疗(IMRT)在靶区和危及器官的剂量学差异及效率的高低。方法:收集HGG病例资料10例,采用Oncentra治疗计划系统对每个病例分别设计5、7、9野IMRT计划和单弧、双弧VMAT(VMAT1、VMAT2)计划,处方剂量为计划靶区(PTV):60 Gy/30 f。(1)比较5、7、9野IMRT计划间PTV和各危及器官的剂量学差异。(2)研究5野IMRT、VMAT1和VMAT2计划间PTV适形指数(CI)、均匀性指数(HI)和危及器官受照量等剂量学差异,比较机器跳数、优化时间和治疗时间等效率参数的差异。结果:(1)5、7、9野IMRT计划:3组计划PTV的CI、HI及各危及器官的最高受量均无统计学差异(P>0.05)。(2)5野IMRT、VMAT1和VMAT2计划:靶区CI分别为0.617±0.076、0.715±0.084和0.731±0.806,有统计学差异(P=0.007),VMAT1和VMAT2组相当,均好于5野IMRT组;靶区HI、最高剂量、最小剂量和D95%无统计学差异(P>0.05);所有危及器官的最高剂量均无统计学差异(P>0.05)。(3)3组计划的机器跳数有统计学差异(P=0.004);计划的优化时间:5野IMRT最快,但VMAT技术耗时;治疗时间:VMAT1最快,只需(3.7±0.5)min,3组计划间有统计学差异(P<0.05)。结论:在HGG术后放疗中,射野数≥5的IMRT计划在PTV和危及器官剂量分布差异不显著;与5野IMRT计划相比,尽管VMAT计划优化时间稍长,但显著提高PTV的CI,且VMAT1计划还具有机器跳数少、治疗时间短的优势。 Objective To compare the dosimetric differences in target areas and organs-at-risk（OAR） and the efficiency between volumetric modulated arc therapy（VMAT） and intensity-modulated radiotherapy（IMRT） for postoperative high-grade glioma（HGG）. Methods Oncentra treatment planning system was used to design 5-, 7-, 9-field IMRT plans and single-and double-arc VMAT（VMAT1 and VMAT2） for 10 postoperative HGG patients. In each plans, the prescription dose was 60 Gy/30 f for planning target volume（PTV）. The dosimetric differences in PTV and OAR were compared among 5-, 7-, 9-field IMRT plans. The conformity index（CI）, homogeneity index（HI） of PTV, the dose of OAR, monitor units, treatment time and optimizing time were compared among 5-field IMRT, VMAT1 and VMAT2 plans. Results No statistical differences were found in the CI and HI of PTV, and the maximum dose（Dmax） of OAR among 5-, 7-, 9-field IMRT plans（P0.05）. VMAT1 and VMAT2 plans showed similar CI of target areas, 0.715±0.084 and 0.731±0.806, respectively, better than 0.617±0.076 in 5-field IMRT plan（comparison among3 plans, P=0.007）. No statistical differences were found in the HI, Dmax, minimum dose and D95%of target areas, and the Dmaxof OAR among 5-field IMRT, VMAT1 and VMAT2 plans（P0.05）. Statistical differences were found in monitor units among 5-field IMRT, VMAT1 and VMAT2 plans（P=0.004）. Optimizing time was shortest in 5-field IMRT plan, longest in VMAT2 plan.The treatment time in VMAT1 plan was only（3.7±0.5） min, with statistical differences among three plans（P0.05）. Conclusion For the postoperative HGG patients, IMRT plans with the number of fields less than 5 doesn＇t show statistical differences in the dose distribution in PTV and OAR. Compared with 5-field IMRT plan, VMAT plan needs longer optimizing time, but achieves better CI in PTV, and VMAT1 has the advantages of smaller monitor units and shorter treatment time.

关 键 词： 高级别脑胶质瘤 图像融合 逆向调强放疗 容积旋转调强放疗 剂量学

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