摘要
目的探讨Monaco治疗计划系统Auto Flash Margin(AFM)在左侧乳腺癌根治术后放疗中的应用。方法选取16例乳腺癌根治术后病例为研究对象,对入组的每个病例分别进行AFM值为0.5、1、2 cm(以下记作AFM0.5、AFM1.0、AFM2.0组)的容积旋转调强(Volumetric Modulated Arc Therapy,VMAT)计划设计。研究放疗计划靶区(Planning Target Volume,PTV)均匀性指数(HomogeneityIndex,HI),适形度指数,肺、心脏及皮肤剂量D_(mean)的剂量学差异,X线蒙特卡罗(X-ray Voxel Monte Carlo,XVMC)算法特征参数等。结果Monaco治疗计划系统蒙特卡罗算法在3种方案中PTV的D_(mean)、V_(107%)剂量学指标均满足处方剂量要求,但差异有统计学意义(P<0.05);靶区热点剂量V_(107%)方面,AFM2.0组最小,为2.57%±1.52%,AFM0.5和AFM1.0组较高且接近,分别为10.09%±1.72%和11.02%±0.15%,差异有统计学意义(P<0.05);靶区D_(mean)表现类似,AFM2.0组最小,为(5175.650±4.200)cGy,AFM0.5和AFM1.0组较高且接近,分别为(5210.400±5.400)cGy和(5219.600±4.200)cGy,差异有统计学意义(P<0.05);在危及器官参数患侧肺V_(20)、患侧肺D_(mean)的剂量评估结果中,AFM0.5组和AFM1.0组均高于AFM2.0组,差异有统计学意义(P<0.05),而3组的健侧肺V_(5)、心脏D_(mean)无明显差异;在组间相同角度下的光栅构型比对中,3组光栅均形成了明显的空气区域;在XVMC算法特征参数比对中,AFM2.0组机器跳数更少、光子利用率更高、优化时长略高,3组的子野数量均接近计划预设的290个控制点。AFM2.0组比另外3组靶区的皮肤组织剂量D_(mean)均更好(P<0.05)。结论使用Monaco治疗计划系统设计乳腺癌根治术后VMAT计划时,推荐使用的AFM值为2 cm。
Objective To investigate the application of Auto Flash Margin(AFM)of Monaco treatment planning system in postoperative radiotherapy for left breast cancer.Methods A total of 16 cases of breast cancer after radical surgery were selected.The plan design of volumetric modulated arc therapy(VMAT)with AFM values of 0.5,1 and 2 cm as AFM0.5,AFM1.0,AFM2.0,was carried out for each enrolled case.The dosimetric differences of planning target volume(PTV)target area homogeneity index(HI),conformity Index,dosimetric differences of lung,heart and skin dose D_(mean)and X-ray voxel Monte Carlo(XVMC)algorithm characteristic parameters of radiotherapy plan were studied.Results The D_(mean)and V_(107%)dosimetric indexes of PTV of Monte-Carlo algorithm in Monaco treatment planning system met the dosage requirements of prescription,but there were statistical differences(P<0.05).In terms of target hot spot dose V_(107%),AFM2.0 group was the smallest(2.57%±1.52%).AFM0.5 and AFM1.0 groups were higher and similar with average value of 10.09%±1.72%and 11.02%±0.15%,The difference was statistically significant(P<0.05).The D_(mean)of the target area was similar,and the smallest was(5175.650±4.200)cGy in AFM2.0 group.AFM0.5 and AFM1.0 groups were higher and closer with average value of(5210.200±5.400)cGy and(5219.600±4.200)cGy,The difference was statistically significant(P<0.05).In the dose evaluation results of Lung_Ipsi V_(20) and Lung_Ipsi D_(mean),AFM0.5 group and AFM1.0 group were higher than AFM2.0 group,and the difference was statistically significant(P<0.05).There were no significant differences in Lung_Contra V_(5) and Heart D_(mean)among the three groups.In the comparison of grating configuration at the same angle,the three groups of gratings all form an obvious air region.In the comparison of XVMC algorithm feature parameters,AFM2.0 group had less monitor unit,higher quantum efficiency and slightly higher optimization time,and the segment of the three groups was close to 290 control points preset in the plan.AFM2.0 group had better D_(mean)than the other three groups(P<0.05).Conclusion When using the Monaco treatment planning system to design the VMAT plan after radical mastectomy,an AFM value of 2 cm is recommended.
作者
华小龙
徐文静
张倜然
葛迅
邹辉
朱磊
包凯
刘庆文
HUA Xiaolong;XU Wenjing;ZHANG Tiran;GE Xun;ZOU Hui;ZHU Lei;BAO Kai;LIU Qingwen(Department of Oncology,XingHua People’s Hospital,Taizhou Jiangsu 225700,China;Thyroid and Breast Surgery,XingHua People’s Hospital,Taizhou Jiangsu 225700,China)
出处
《中国医疗设备》
2024年第4期53-59,共7页
China Medical Devices
基金
2021年度泰州市科技支撑计划社会发展项目(202118)。
关键词
乳腺癌根治术后
蒙特卡罗算法
容积调强
剂量分布
postoperative radiotherapy
Monte Carlo algorithm
volumetric strengthening
dose distribution
