基于品质因素评价瓦里安锥束CT成像质量与辐射剂量风险收益比  

Evaluation of cost-effective ratio(imaging quality vs.radiation dose)of Varian cone beam CT based on figure of merit(FOM)

作　　者：李俊禹 吴昊[1] 杨敬贤[1] 李廷廷 于松茂 卢子红 王美娇[1] 李晨光 李玮博 张艺宝[1] Li Junyu;Wu Hao;Yang Jingxian;Li Tingting;Yu Songmao;Lu Zihong;Wang Meijiao;Li Chenguang;Li Weibo;Zhang Yibao(Key Laboratory of Carcinogenesis and Translational Research(Ministry of Education/Beijing),Department of Radiation Oncology,Peking University Cancer Hospital&Institute,Beijing 100142,China;The Fifth Medical Center of PLA General Hospital,Beijing 100039,China;Institute of Radiation Medicine,Helmholtz Zentrum München-German Research Center for Environmental Health(GmbH),Neuherberg 185764,Germany)

机构地区：[1]北京大学肿瘤医院暨北京市肿瘤防治研究所放疗科,恶性肿瘤发病机制及转化研究教育部重点实验室,100142 [2]解放军总医院第五医学中心,北京100039 [3]Institute of Radiation Medicine,Helmholtz Zentrum München-German Research Center for Environmental Health(GmbH),Neuherberg 185764,Germany

出　　处：《中华放射医学与防护杂志》2020年第8期595-599,共5页Chinese Journal of Radiological Medicine and Protection

基　　金：首都卫生发展科研专项(首发2018-4-1027);教育部科技发展中心产学研创新基金-"智融兴教"基金(2018A01019);国家自然科学基金(11505012,11905150,81672969);国家重点研发计划(2019YFF01014405);四川省科技计划(2018HH0099);北京市自然科学基金(7172048,1202009)。

摘　　要：目的分析比对不同Varian加速器平台机载千伏锥束CT(kV CBCT)系统的辐射剂量和成像质量,指导临床选用风险收益比(成像质量/辐射剂量)最高的图像引导方案。方法利用CT剂量指数模体(CTDI模体)和CT电离室,以及Catphan604模体分别获取Edge、Truebeam、新旧两台ix加速器机载CBCT典型扫描模式的辐射剂量和成像质量参数,使用品质因素(figure of merit,FOM)值评估各图像引导方案的风险收益比。结果不同型号的瓦里安加速器配置的kV CBCT系统的FOM不同,差异广泛分布于0.65(温和成像一圈)~48.46(温和成像半圈)区间;各扫描参数间FOM也存在较大差异,均值为22.14±13.47。结论由于设备间和参数间存在显著差异,基于实际测量的验证评估有助于临床选择合理的影像引导方案,剂量敏感患者应优先选择加权CT剂量指数(CTDIw)低的参数和设备;对图像质量要求高的患者应优选对比度噪声比(CNR)高的方案;而普通患者则可依据风险收益比进行选择,此时品质因素FOM可为临床决策提供有利工具。Objective To analyze and compare the radiation dose and image quality of kilo-voltage cone beam CT systems on different Varian accelerator platforms,providing data to support clinical decisions on selecting optimal protocols for image-guided radiotherapy based on cost-effective ratio(image quality/radiation dose).Methods The radiation dose and image quality of various CBCT systems and scanning protocols on Varian Edge,Truebeam and ix(new and old)LINACs were obtained using a CT dose index(CTDI)phantom combined with a CT ionization chamber and a Catphan604 phantom,respectively.Figure of merit(FOM)was used to evaluate the cost-effective ratio of the image guidance schemes.Results Considerable inter-system varieties of FOMs were observed,varying from 0.65(Image Gently-full trajectory)to 48.46(Image Gently-half trajectory).The inter-protocol varieties were also large,where the mean±SD was 22.14±13.47.Conclusions Considering the explicit inter-system and inter-protocol varieties,it is clinically favorable to evaluate the image guidance schemes based on machine-specific measurement.For instance,parameters and equipment with low CTDIw can be beneficial for dose-sensitive patients.High CNR regimen favors patients with high image quality requirements.For ordinary patients,cost-effective ratio in terms of FOM can be very helpful to guide the decision-making of clinical image-guided radiotherapy.

关 键 词：图像引导放疗 千伏锥形束CT 辐射剂量 成像质量 

分 类 号：R730.55[医药卫生—肿瘤]