于浪;杨波;孙玉亮;孙显松;王欣海;李文博;姜斐;李楠;邱杰;张福泉;
YU Lang;YANG Bo;SUN Yu-liang;SUN Xian-song;WANG Xin-hai;LI Wen-bo;JIANG Fei;LI Nan;QIU Jie;ZHANG Fu-quan;Department of Radiation Oncology,Peking Union Medical College Hospital,Chinese Academy of Medical Sciences &Peking Union Medical College;

• 1:中国医学科学院北京协和医学院北京协和医院放射治疗科

摘要(Abstract)：

目的探讨Checkmate 2作为日检工具用于放射治疗加速器输出剂量检测的可行性。方法按照国际原子能机构(International Atomic Energy Agency,IAEA)第277号报告建议方法刻度Varian 2300CD加速器的两档光子线6、15 MV及五档电子线6、9、12、16、20 Me V,每日分别使用指型电离室和Checkmate 2测量各档能量100 MU的输出量,得出各自剂量偏差,最大允许偏差为±2%。分别实测环境温度气压值和读取Checkmate 2温度气压显示值,计算温度气压修正因子。连续进行3个月工作日共66次测量,比较每日各档能量测量值以及温度气压修正准确性。结果各档能量的电子线及X射线的Checkmate 2与指型电离室测量结果均满足绝对剂量偏差不超过2%的标准,且两者比较差异均无统计学意义(P>0.05)。实测及Checkmate 2测量得出的平均温度气压修正因子分别为1.032±0.007和1.033±0.007,两者差异无统计学意义(P=0.452);相关性分析显示两者呈正相关(r=0.92,P=0.000)。结论 Checkmate 2可真实反映加速器剂量输出的大体趋势,且测量工作耗时短、操作简便,是直线加速器晨检剂量输出检测的良好工具。
Objective To discuss the feasibility of Checkmate 2 as a daily check device in radiotherapy accelerator output check. Methods According to the methods proposed in International Atomic Energy Agency( IAEA) Report No. 277,Varian 2300 CD accelerator's two photon beams( 6 MV and 15 MV) and 5 electronic beams( 6,9,12,16,and 20 Me V) were calibrated. Ionization chamber and Checkmate 2 were used to measure the output of the beam at 7 energies delivering 100 MU every day. Maximum permissible error was ± 2%. Ambient temperature and air pressure were measured and also detected by Checkmate 2 to calculate the correction factor. A total of 66 continuous measurements were carried out in workdays in 3 months to compare the measurements at different energies and accuracy of temperature and air pressure correction factor every day. Results In the measurement results of both Checkmate 2 and ionization chamber,the absolute dose errors were within 2%,and the differences between the two measurement results showed no statistically significant difference( P > 0. 05).Measured and Checkmate 2-calculated mean temperature and pressure correction factor were 1. 032 ± 0. 007 and1. 033 ± 0. 007,respectively,with no significant difference( P = 0. 452). Correlation analysis showed that the two correction factors were positively correlated( r = 0. 92,P = 0. 000). Conclusions Checkmate 2 could re-flect the dose output with short measurement time and simple operation. It may be applied as a very useful device for linear accelerator output morning check.

关键词(KeyWords)： 加速器;晨检;输出剂量;Checkmate 2
accelerator;morning check;output dose;Checkmate 2

Abstract:

Keywords:

基金项目(Foundation):

作者(Authors): 于浪;杨波;孙玉亮;孙显松;王欣海;李文博;姜斐;李楠;邱杰;张福泉;
YU Lang;YANG Bo;SUN Yu-liang;SUN Xian-song;WANG Xin-hai;LI Wen-bo;JIANG Fei;LI Nan;QIU Jie;ZHANG Fu-quan;Department of Radiation Oncology,Peking Union Medical College Hospital,Chinese Academy of Medical Sciences &Peking Union Medical College;

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