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.
出处
《中国医学物理学杂志》
CSCD
2017年第7期719-725,752,共8页
Chinese Journal of Medical Physics
基金
深圳市卫生计生系统科研项目(201401012)
深圳市科创委科研课题(JCYJ20150403102020235)
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
high-grade glioma
image fusion
intensity-modulated radiotherapy
volumetric modulated arc therapy
dosimetry
作者简介
李壮玲，硕士研究生，主管技师，主要研究方向：肿瘤放射治疗学，E．mail：lizhuangling@163．com
钟鹤立，高级工程师，E—mail：zhongheli@tom．com
