基于井型电离室源驻留位置和驻留时间检测方法研究

Study of the verification of the source positioning and dwelling time based on the well-chamber

目的研究利用井型电离室,以剂量学的方式,对后装治疗机源驻留位置和驻留时间精度进行验证,为后装治疗机的质控提供一种新方法。方法基于井型电离室的硬件结构,分析井型电离室测量的原理,通过模拟测试和数据拟合分析其检测精度,并进行稳定性测试。通过与传统方法比较,总结优缺点。结果源到位精度检测准确度较高,可以精确到0.07 mm,驻留时间检测可以精确到0.09 s。稳定性测试实验中测量值相对标准偏差<3%。结论井型电离室方法可用于后装治疗机源驻留位置和驻留时间的快速相对验证,是一种精度较高、操作简便的方法。

Objective To establish a dosimetric method based on the well-chamber to verify the accuracy of the source positioning and dwelling time for the afterloading machine,aiming to provide a new method for the quality control of afterloading machine.Methods The principle of this method was explained according to the hardware structure of the well-chamber.Then,the precision of this method was analyzed by the simulation test and data fitting.The feasibility test was also performed.And the advantages and disadvantages of this method were compared with those of the traditional method.Results The precision of this method for detecting the source positioning was 0.07 mm and the dwelling time was 0.09 s,respectively.In the feasibility test,the standard deviation of the measure value was below 3%.Conclusions The well-chamber method has high precision and convenient operation.It can be applied in the rapid verification of the relative accuracy of the source positioning and dwelling time of well-chamber.