基于国际原子能机构277和381报告对直线加速器双模式光子线和电子线输出量校准研究  

Study on the calibration for the outputs of photon and electron beams of dual-mode of linear accelerator based on IAEA 277 and 381 reports

作　　者：景周 陈幼芬[1] 程杭 蔡佳彬 张磊 康德华[3] Jing Zhou;Chen Youfen;Cheng Hang;Cai Jiabin;Zhang Lei;Kang Dehua(Department of Radiotherapy Technology,Yuyao People’s Hospital of Zhejiang Province,Ningbo 315400,China;Department of Radiation Physics,Zhejiang Cancer Hospital,Hangzhou 310022,China;Department of Radiotherapy,Sun Yat-Sen University Cancer Center,Guangzhou 510060,China)

机构地区：[1]余姚市人民医院放疗技术科,宁波315400 [2]浙江省肿瘤医院放射物理科,杭州310022 [3]中山大学肿瘤防治中心放疗科,广州510060

出　　处：《中国医学装备》2024年第1期29-33,共5页China Medical Equipment

基　　金：浙江省医药卫生科技计划(2023XY161)。

摘　　要：目的:基于国际原子能机构(IAEA)TRS 277和TRS 381《高能电子束和光子束中使用平行电离室的国际剂量测定操作规范》报告,校准加速器配置的不同档能量射线水中的吸收剂量,确保临床放疗中直线加速器输出剂量的精确性。方法:采用Elekta Infinity直线加速器,光子线能量6 MV分别为均整(FF)模式和非均整(FFF)模式;电子线能量分别为4、6、8、10、12和15 MeV。根据IAEATRS277和TRS381报告,使用PTW剂量仪、PTW30013指型电离室和PTW34001平行板电离室分别进行光子线和电子线水中输出剂量的校准,对各步骤的误差进行分析,对比采用不同标准对直线加速器的输出量水中校准的准确性。结果:6 MV的FF模式和FFF模式光子线在水中最大剂量点处的输出量分别为1.003和1.008 cGy/MU;4、6、8、10、12和15 MeV的电子线每档能量在水中最大剂量点处的输出量分别为1.003、1.002、0.998、0.999、1.000和1.003 cGy/MU。每档能量的射线在水中最大剂量点处的输出量校准为1 MU对应1 cCy,误差<1%。结论:根据IAEA TRS277号和TRS381号报告对直线加速器的输出剂量在水中进行校准,可以保证直线加速器的输出剂量的准确性。Objective:To calibrate the absorbed doses of the configured ray water with different gears of energies in accelerator based on<The use of plane-parallel ionization chambers in high-energy electron and photon beams>of International Atomic Energy Agency(IAEA)277 and 381 reports,so as to ensure the accuracy of the output dose of the linear accelerator during clinical radiotherapy.Methods:Elekta Infinity linear accelerator was used in this study,and the photon beam energies were respectively 6MV flattening filter(FF)mode and 6MV flattening filter free(FFF)mode.The electron beam energies were respectively 4,6,8,10,12 and 15MeV.According to the IAEA TRS277 and TRS381 reports,the calibrations of output doses in photon and electron beam waters were performed respectively by using the PTW dosimeter,PTW30013 finger type of ionization chamber and PTW34001 parallel plate ionization chamber.The error of each step was analyzed,and the accuracies of the calibrations of using different standards for the output waters of linear accelerator were compared.Results:The output amounts of photon beams of FF mode and FFF mode of 6MV at the maximum dose point in water were respectively 1.003 and 1.008cGy/MU.The output amounts of the energy of each gear of electron beams of 4,6,8,10,12 and 15MeV at the maximum dose point in water were respectively 1.003,1.002,0.998,0.999,1.000 and 1.003 cGy/MU.The calibration of the output of each gear of energy rays at the maximum dose point in water was 1cCy corresponded to 1MU,which error was less than 1%.Conclusion:The calibration for the output dose amount of accelerator in water on the basis of IAEA TRS277 and trs381 can ensure the accuracy of the output dose of the accelerator.

关 键 词：输出量校准 国际原子能机构(IAEA)TRS277和TRS381报告 电子线 光子线 均整模式 非均整模式 

分 类 号：R812[医药卫生—放射医学]