基于IAEA277号报告对Versa HD直线加速器的剂量校准  

Absorbed Dose Calibration for Versa HD Linac Based on IAEA277 Report

作　　者：卢小开[1] 张广武[1] 冯志宇[1] 李云[1] 薛小峰 Lu Xiaokai;Zhang Guangwu;Feng Zhiyu;Li Yun;Xue Xiaofeng(Radiation Oncology Department,Guizhou Provincial People’s Hospital,Guiyang Guizhou 550002,China)

机构地区：[1]贵州省人民医院肿瘤科,贵阳550002

出　　处：《医疗装备》2018年第11期21-23,共3页Medical Equipment

摘　　要：目的为了保证吸收剂量的准确,基于IAEA277号报告对Versa HD直线加速器的输出剂量进行标定。方法采用IAEA TRS277号报告推荐的电离室测定方法,对Versa HD直线加速器的6 MV,6 FFF,10 M,10 FFF四档光子线以及五档能量的电子线进行吸收剂量校准,确保在源皮距100 cm,10 cm×10 cm辐射野条件下加速器光子线和电子线出束100 MU,水下最大剂量点处的吸收剂量为100 c Gy。结果光子线吸收剂量在标定前高于标准剂量,电子线在标定前低于标准剂量;光子线在经过均整器后射线质有所增加;经过调整加速器的电位后最大剂量点吸收剂量在(100±1)c Gy范围内。结论吸收剂量标定是放疗的关键环节,也是物理师的职责所在,准确的剂量标定是确保辐射安全的前提。Objective To perform dose calibration of absorbed dose on Versa HD linear accelerator(linac),according to International Atomic Energy Agency(IAEA)277 Report.Methods Used the ionization chamber measurement method recommended by IAEA TRS_277 report.Absorbed dose calibration was performed on the Versa HD linac with four photon energies(6 M,6 FFF,10 M,10 FFF)and five electronic energies to make sure that under the condition of SSD=100 cm,10 cm×10 cm radiationfield,the maximum absorbed dose underwater was 100 cGy=100 Mu.Results The absorbed dose of photon beams were higher than the standard dose before calibration,while that of electronic beams were lower than the standard dose before calibration.The beam quality increased after using flattening filter;after adjusting potential of the accelerator,the absorbed dose value of maximum dose point depth was within the range of(100±1)cGy.Conclusion Absorbed dose calibration is a key link in the process of radiotherapy,and is also the responsibility of the physicist.Accurate dose calibration is a prerequisite to ensure radiation safety.

关 键 词：VERSA HD直线加速器 277号报告 吸收剂量校准 水模体 

分 类 号：R815[医药卫生—放射医学]