摘要
放疗过程中,利用塑料闪烁光纤剂量计(Plastic Scintillator Fiber Dosimeters,PSFDs)对患者关键健康组织及肿瘤进行实时、高位置分辨的介入式剂量测量是质量保证(Quality Assurance,QA)最直接的手段之一。为研究PSFDs的实际应用情况,研制一套基于连续剂量读出的实用型塑料闪烁光纤剂量计。该剂量计以硅光电倍增管(Silicon Photomultiplier,SiPM)作为光电转换器件,通过测量SiPM输出电流实现剂量测量。利用发光二极管(Light Emitting Diode,LED)脉冲光源与小动物图像引导放射治疗机,对该剂量计的时间稳定性、重复性、温度响应、白光纤曲率响应以及动态范围等进行了系统研究。实验结果表明:恒温20℃,剂量计8 h内连续工作,输出电流变化小于1%,32 h间断工作输出电流变化小于0.5%;温度变化小于0.5℃,白光纤曲率半径大于11 cm,输出电流变化小于1%;剂量计线性动态范围可达100~9 000 cGy?min?1。该剂量计基本满足临床剂量验证的要求。
[Background]A real-time,high position resolved in-vivo dose measurement of critical health tissues and tumors is one of the most direct quality assurance(QA)tools in the radiotherapy.Plastic scintillator fiber dosimeters(PSFDs)have great advantages in dose verification due to its small size,good radiation resistance and good tissue equivalence.[Purpose]This study aims to develop a plastic scintillation fiber dosimeter(PSFD)based on silicon photomultiplier(SiPM),and investigate its performance in clinical applications.[Methods]With a stable LED pulse optical source,the leakage current of SiPM was measured by the picoammeter.Time stability and repeatability of the dosimeter,temperature response and the influence of the transmission fiber curvature on the SiPM leakage current were systematically studied.The dynamic range of the dosimeter was measured by using a small animal radiotherapy machine and LED pulse optical source.[Results]The results show that the leakage current changes<1%when the dosimeter works continuously for 8 h at constant temperature of 20℃,and the leakage current changes<0.5%during 32 h of intermittent operation.When the temperature change is less than 0.5℃,or the transmission fiber radius of curvature is greater than 11 cm,the output current change is less than 1%.The linear dynamic range of the dosimeter measurement is 100~9 000 cGy?min?1.[Conclusions]The developed dosimeter basically meets the accuracy requirements of the clinical dose verification.
作者
杨翠萍
辛杰
周冬冬
李一秋
柴林
尤思梅
张保国
文万信
张明
王仁生
YANG Cuiping;XIN Jie;ZHOU Dongdong;LI Yiqiu;CHAI Lin;YOU Simei;ZHANG Baoguo;WENWanxin;ZHANG Ming;WANG Rensheng(School of Radiation Medicine and Protection,Medical College of Soochow University,Suzhou 215123,China;Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions,Suzhou 215123,China;The First Affiliated Hospital of Soochow University,Suzhou 215006,China;Division of Ionizing Radiation,National Institute of Metrology,Beijing 100029,China;Nanjing Brain Hospital,Nanjing 210029,China)
出处
《核技术》
CAS
CSCD
北大核心
2019年第10期39-45,共7页
Nuclear Techniques
基金
国家重点研发计划(No.2017YFF0206205)
国家自然科学基金青年基金项目(No.11605119)
江苏省自然科学基金青年项目(No.BK20160304)
国家博后基金面上项目(No.2017M621818)资助~~
