摘要
目的比较剂量计算网格(Dose Calculation Grid Size,DCGS)大小对基于容积旋转弧形调强放疗技术(Volumetric Modulate Arc Therapy,VMAT)的脑肿瘤立体定向放疗(Steretactic Radiotherapy,SRT)剂量学参数和优化效率的影响,探索将SRT技术应用于脑肿瘤时最优的计算网格大小。方法选取10例SRT脑肿瘤患者,均采用VMAT技术,处方剂量40 Gy,靶区体积范围2.8~37.7 cm^(3),相同优化条件下分别使用0.1、0.2和0.3 cm(DCGS1、DCGS2和DCGS3组)的剂量计算网格进行计划设计和评估。比较3组计划靶区的D_(95)、D_(50)、梯度指数(Gradient Index,GI)、适形度指数、危及器官的受照剂量、机器跳数和剂量计算时间。结果DCGS1组的靶区GI和正常脑组织V_(5)、V_(10)、V_(15)、V_(20)、V_(25)和D_(mean)均优于DCGS2和DCGS3组,与DCGS2相比分别下降了0.26、1.44%、1.23%、0.52%、0.25%、0.14%以及0.20 Gy(P<0.05),与DCGS3相比分别下降了0.60、3.11%、2.85%、1.25%、0.60%、0.33%以及0.45 Gy(P<0.05)。DCGS1、DCGS2和DCGS3组的剂量计算时间分别为46.85、12.29和5.36 min。DCGS3组与DCGS2组和DCGS1组相比,计算时间分别降低了56.39%和88.56%(P<0.05)。结论综合考虑计划质量和优化效率,建议采用0.2 cm计算网格用于脑肿瘤SRT,若只考虑计划质量则建议采用0.1 cm计算网格。
Objective To compare the effect of dose calculation grid size(DCGS)on dosimetric parameters and optimization efficiency of brain tumor stereotactic radiotherapy(SRT)based on volumetric modulated arc therapy(VMAT),and explore the optimal DCGS for brain tumor SRT.Methods A total of 10 patients with brain tumors were selected.All patients received VMAT at a prescription dose of 40 Gy and target volume range of 2.8~37.7 cm^(3).Under the same optimization conditions,dose calculation grids of 0.1,0.2 and 0.3 cm(DCGS1,DCGS2 and DCGS3 groups)were used for planning design and evaluation.The difference for D_(95),D_(50),gradient index(GI),conformity index(CI),dose to OARs,monitor unit and dose calculation time were compared among these 3 treatment plans.Results The GI of target area and the V_(5)、V_(10)、V_(15)、V_(20)、V_(25) and D_(mean) of normal brain tissue in DCGS1 group were better than those in DCGS2 and DCGS3 group.Compared with DCGS2,they decreased by 0.26,1.44%,1.23%,0.52%,0.25%,0.14%and 0.20 Gy respectively(P<0.05).Compared with DCGS3,they decreased by 0.60,3.11%,2.85%,1.25%,0.60%,0.33%and 0.45 Gy,respectively(P<0.05).The dose calculation time of DCGS1,DCGS2 and DCGS3 groups were 46.85,12.29 and 5.36 min,respectively.Compared with DCGS2 and DCGS1,the calculation time of DCGS3 group was reduced by 56.39%and 88.56%(P<0.05),respectively.The dose calculation time was 46.85,12.29 and 5.36 min for DCGS1,DCGS2 and DCGS3,respectively.DCGS3 compared with DCGS2 and DCGS1,the dose calculation time decreased by 56.39%and 88.56%,respectively(P<0.05).Conclusion Considering planning quality and optimization efficiency,a 0.2cm grid is recommended for SRT of brain tumors,and a 0.1cm grid is recommended for SRT of brain tumors only considering planning quality.
作者
刘力闽
陈馨薇
罗静
康盛伟
黎杰
王培
吴骏翔
LIU Limin;CHEN Xinwei;LUO Jing;KANG Shengwei;LI Jie;WANG Pei;WU Junxiang(Department of Oncology,The People’s Hospital of Renshou County,Renshou Sichuan 620500,China;Key Laboratory of Radiation Oncology of Sichuan Province,Sichuan Cancer Hospital&Institute/Sichuan Cancer Center/School of Medicine,UESTC,Chengdu Sichuan 610041,China)
出处
《中国医疗设备》
2022年第4期47-50,共4页
China Medical Devices
基金
四川省重点研发项目(2021YFG0168,2021YFG0320)。
关键词
立体定向放疗
容积弧形调强放射治疗
剂量计算网格
剂量学参数
脑肿瘤
stereotactic radiotherapy
volumetric modulated arc therapy
dose calculation grid
dosimetric parameters
brain tumor
