光致发光剂量计角响应研究  

Angular dependence of the optically stimulated luminescent dosimeter

作　　者：王琦 袁继龙[1] 郭朝晖[1] 程金生[1] WANG Qi;YUAN Jilong;GUO Zhaohui;CHENG Jinsheng(Key Laboratory of Radiological Protection and Nuclear Emergency,China CDC,National Institute for Radiological Protection,Chinese Center for Disease Control and Prevention,Beijing 100088 China)

机构地区：[1]中国疾病预防控制中心辐射防护与核安全医学所辐射防护与核应急中国疾病预防控制中心重点实验室,北京100088

出　　处：《中国辐射卫生》2021年第1期38-43,共6页Chinese Journal of Radiological Health

基　　金：创新医疗器械示范应用评价体系研究(2019YFC0121803)。

摘　　要：目的结合定制固体模体研究光致发光剂量计(OSLD)在放疗水平60Co标准辐射场中的角响应性能,探讨OSLD在容积旋转调强放射治疗(VMAT)等旋转照射剂量核查中应用的可行性。方法将OSLD嵌入2个外观尺寸以及材料均相同的定制固体模体,模体1使OSLD与射线垂直,模体2使OSLD与射线平行,照射8个角度:0°、45°、90°、135°、180°、-45°、-90°和-135°,读取每个角度的OSLD计数,计算每个角度相对于0°的角响应值。结果当OSLD垂直于射线照射时,角响应在-6.76%~+1.5%,90°和-90°角响应最大;当OSLD平行于射线照射时,角响应在-1.74%~+1.67%,均在±2%以内。结论在实际工作中,应先计算元件校正因子(ECF),校正各剂量计对射线的灵敏度,旋转照射条件下,将OSLD平行于射线入射方向放置,能更好地降低角响应影响,便于进一步开展VMAT剂量核查应用研究。0bjective To study the angular dependence of optically stimulated luminescent dosimeter(OSLD)with solid phantoms under SSDL radiation level 60 Co radiation field,and to discuss the possibility of OSLD in volumetric modulated arc therapy(VMAT)and other rotating irradiation dose audit.Methods OSLDs were embedded in the two phantoms with the same size and material,respectively.The phantom 1 was set to make the first OSLD perpendicular to the beam,and the phantom 2 was set to make the second OSLD parallel to the beam.The OSLDs were irradiated at 8 angles:0°,45°,90°,135°,180°,-45°,-90,-135°.The counts of the OSLSs were read and the response of each angle which normalized to 0°were calculated.Results When the OSLDs are perpendicular to the beam,the angular response is between-6.76%~+1.5%,with the maximum angular dependence at 90°and-90°.When the OSLDs are parallel to the beam,the angular response is between-1.74%~+1.67%,below 2%.Conclusion It is better to correct the sensitivity of dosimeters by Element Correction Factors(ECF)for dose audit.Under the condition of rotating irradiation,OSLD shoud be set parallel to the beam,which can better reduce the influence of angular dependence and facilitate further application research of VMAT dose audit.

关 键 词：OSLD 角响应 剂量核查 VMAT 

分 类 号：TL818.7[核科学技术—核技术及应用]