基于DVH重建模型评估三维γ法则在剂量验证中的可靠性  

Based on DVH reconstruction system to investigate the reliability of three-dimensions gamma rule

作　　者：马阳光[1,3] 刘乐乐 裴运通[1] 牟轩沁 顾浩[2] 郭跃信[1] MA Yangguang;LIU Lele;PEI Yuntong;MOU xuanqin;GU Hao;GUO Yuexin(First Affiliated Hospital,Zhengzhou University,Zhengzhou,Henan450052,China;School of Information and Communications Engineering,Xi'an JiaoTong University,Xi'an,Shaanxi 710049,China)

机构地区：[1]郑州大学第一附属医院放射治疗部,河南郑州450052 [2]郑州大学第一附属医院放疗一科,河南郑州450052 [3]西安交通大学信息与通信工程学院,陕西西安710049

出　　处：《中华肿瘤防治杂志》2024年第9期556-562,共7页Chinese Journal of Cancer Prevention and Treatment

基　　金：河南省医学科技攻关省部共建重点项目(SBGJ202102102);河南省高端外国专家引进计划(HNGD2022030)。

摘　　要：目的构建及评估VeriSoft剂量体积直方图(DVH)重建模型,并基于此模型探讨三维γ在剂量验证评估中的可靠性。方法建立Octavius 4D1500DVH重建模型,使用固定及旋转野照射由固体水、Razor电离室、EBT3胶片、自制泡沫构建的模体,采用测量及DVH重建结果验证模型准确性。选取郑州大学第一附属医院2022-07-01-2022-12-31容积旋转调强技术(VMAT)治疗的肺腺癌患者20例,男8例,女12例,中位年龄58岁。所有患者均采用Monaco计划,VersaHD投照并用1500阵列测量。在10%阈值、3%/3mm~1%/1mm任意组合标准时计算实测、计划剂量间全局、局部三维γ通过率。用VeriSoft DVH由实测及患者计划信息重建评估各器官DVH偏差。最后将所得偏差同上述γ通过率做相关分析。结果Razor、EBT3测量、DVH重建与计划剂量偏差<4.46%。全局γ3%/2mm评估时检测出3例大偏差测试。PTV、CTV、GTV平均剂量偏差小,心脏V30Gy、V40Gy及患侧肺最大剂量平均偏差大,分别为9.27%、14.25%和9.51%。心脏平均剂量偏差与所有γ通过率呈极强相关,靶区中仅GTV平均剂量与γ通过率程中等强度相关。结论DVH重建模型构建方法可靠,所建模型准确。基于Octavius 4D三维γ评估剂量验证会出现假阴性,建议将其与VeriSoft DVH重建共同用于剂量验证评估。Objective To establish and validate the model of VeriSoft DVH,then based on this mode,reliability of three dimensions gamma rule in evaluating the dose verification results was investigated.Methods DVH model of Octavius 4D 1500system was build first.Then,modules composed of solid water,EBT3film,homemade foam and ionization chamber(Razor)were established.These modules,together with fixed and rotational fields were used to verify the accuracy of DVH model.After that,twenty lung cancer patients were chosen from First Affiliated Hospital of Zhengzhou University whose treatment plans generated by Monaco were delivered by VersaHD Linac and were performed on Octavius 4D1500 system respectively.Dose calculated in radiotherapy plan and measured results were compared for these patients.Onetenth of the maximum dose was set as the threshold value,and 3%/3mm,3%/2mm,2%/3mm,2%/2mm,1%/2mm,2%/1mm,1%/1mm were selected to calculate the global and local three dimensionsγpass-rate.The DVH difference between Monaco calculate and reconstruction by VeriSoft DVH were also evaluated.Results Dose deviation between reconstructed and Monaco calculated,and dose difference between measured and Monaco calculated were both less than 4.46%,indicating that the DVH model was reliable.Three of the cases with large dose deviations were found using the global gamma with 3%/2mm.Average value of the mean dose difference to the targets was small.To the OARs,V30Gyand V40Gyof the heart and maximum dose of the affected lung have large average deviation up to 9.27%,14.25%and 9.51%.High correlation was only found between the heart mean dose deviation and allγpass rates,and moderate correlation was found between GTV mean dose deviation and allγpass rate.To other dose deviations,no correlation was found between them and correspondγpass rate.Conclusions The DVH model is established accuracy though a reliable process and its reliability is validated.The gamma evaluated based on Octavius 4Dis reliable in most cases,but a false negative result would occur by ac

关 键 词：剂量体积直方图重建模型 剂量验证 三维γ评估 肺癌 

分 类 号：R730.55[医药卫生—肿瘤] R734.2[医药卫生—临床医学]