基于MONACO计划系统有无均整器模式对直肠癌术后SIB-VMAT计划影响的研究  

Dosimetric Comparison of the SIB-VMAT for Rectal Cancer Using Flattening Filter Mode and Flattening Filter Free Mode in MONACO Treatment Planning System

作　　者：葛双 郗会珍 陈长建[1] 李慧[2] 王寻 马俊 程锦绣 魏敏 朱培军[1] 程淑媛 杨君东[1] 叶书成[1,2] GE Shuang;CHI Huizhen;CHEN Changjian;LI Hui;WANG Xun;MA Jun;CHENG Jinxiu;WEI Min;ZHU Peijun;CHENG Shuyuan;YANG Jundong;YE Shucheng(Department of Tumor Radiotherapy,The Affiliated Hospital of Jining Medical University,Jining Shandong 272001,China;Department of Tumor,The Affiliated Hospital of Jining Medical University,Jining Shandong 272001,China;Department of Medical Imaging,The Affiliated Hospital of Jining Medical University,Jining Shandong 272001,China)

机构地区：[1]济宁医学院附属医院肿瘤放疗科,山东济宁272001 [2]济宁医学院附属医院肿瘤科,山东济宁272001 [3]济宁医学院附属医院医学影像中心,山东济宁272001

出　　处：《中国医疗设备》2022年第3期43-47,51,共6页China Medical Devices

基　　金：中华国际医学交流基金会肿瘤精准放疗星火计划科研项目(2019-N-11-22);济宁医学院附属医院苗圃科研计划(MP-2016-004,MP-2018-024)。

摘　　要：目的探讨直肠癌术后患者在6 MV光子束均整(Flattening Filter,FF)与非均整(Flattening Filter Free,FFF)模式下行瘤床同期加量容积旋转调强放射治疗(Simultaneous Integrated Boost of Volumetric-Modulated Arc Therapy,SIB-VMAT)的剂量学差异。方法随机选取16例直肠癌术后患者,在相同约束条件下分别设计FF和FFF模式的SIB-VMAT计划,剂量验证采用MatriXX探测器进行测量。比较两组计划的剂量-体积参数,靶区均匀性指数(Homogeneity Index,HI)和适形性指数(Conformity Index,CI)、机器跳数(Monitor Unit,MU)、控制点数(Control Point,CP)、出束时间以及γ通过率。结果在保证PTV95%体积接受100%处方剂量的标准下,与FF模式相比,FFF模式可降低PGTV高剂量区D_(2%)和PTV的D_(mean)及D_(50%)约1%,提高PTV低剂量区D_(98%)约0.63%,改善PTV的CI和HI,减少肠道的D_(max)、V_(45)以及膀胱的辐射剂量,同时明显降低靶区外部25 Gy、22.5 Gy覆盖体积以及靶区间(P-G)的D_(mean),差异均有统计学意义(P<0.05)。与FFF模式相比,FF的MU与CP明显降低,差异有统计学意义(P<0.05),但两组计划的出束时间相近,差异无统计学意义(P>0.05);在剂量输出验证方面,两组计划的γ通过率在3%/3 mm标准下均大于99%,差异无统计学意义(P>0.05);但在2%/2 mm和1%/1 mm标准下,FFF模式的γ通过率结果均明显提高,差异有统计学意义(P<0.05)。结论两组计划均能满足临床要求,相对于FF模式,FFF模式在提高计划质量,保护膀胱和肠道方面更有明显优势。Objective To investigate the dosimetric difference of the simultaneous integrated boost of volumetric-modulated arc therapy(SIB-VMAT)for rectal cancer using 6 MV flattening filter(FF)mode and flattening filter free(FFF)mode.Methods A total of sixteen patients with rectal cancer were randomly selected to design SIB-VMAT plans with FF and FFF modes under the same constraints.The dose verification was measured by MatriXX detector.The homogeneity index(HI),conformity index(CI)of targets,monitor unit(MU),control point(CP),beam time andγpass rate were compared.Results Under the standard of 100%of the prescribed dose to cover 95%of the PTV volume,the D_(2%)of the PGTV,the D_(mean) and D_(50%)of the PTV were decreased by 1%compared with the FF modes.The D_(98%)of PTV was increased by 0.63%.The CI and HI of PTV were improved.The D_(max) and V_(45) of the intestine and the radiation dose in bladder reduced.The coverage volumes of peripheral dose by 25 Gy,22.5 Gy and the D_(mean) of between target area(P-G)were significantly decreased,with statistical significance(P<0.05).Compared with FFF mode,MU and CP in FF mode were significantly decreased and the difference was statistically significant(P<0.05).But the planned beam delivery time was similar,and the difference was not statistically significant(P>0.05).Theγpass rate verified by the plan were all greater than 99%under the criteria of 3%/3 mm.The difference was not statistically significant(P>0.05).But under the criteria of the 2%/2 mm and 1%/1 mm,theγpass rate of the FFF model was significantly increased and the difference was statistically significant(P<0.05).Conclusion The plans of the two modes can meet the clinical requirements.Compared with the FF mode,the FFF mode has obvious advantages in improving the quality of the plan and protecting the bladder and intestines.

关 键 词：直肠癌 容积旋转调强 非均整射模式 剂量学 

分 类 号：R735.37[医药卫生—肿瘤]