Technical Note: Characteristics of a microSilicon X shielded diode detector for photon beam dosimetry
Technical Note: Characteristics of a microSilicon X shielded diode detector for photon beam dosimetry
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DOI：
10.1002/mp.14639
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发表时间：
2021-03-06
期刊：
影响因子：
3.8
通讯作者：
Ogawa, Kazuhiko
中科院分区：
文献类型：
--
作者：
Akino, Yuichi;Okamura, Keita;Ogawa, Kazuhiko
目的研究新型屏蔽二极管探测器MicroSiliconX（型号60022：方法测量了深度剂量百分比（PDD）、束流剖面、探测器输出因子（OFdet）、温度依赖性、剂量率依赖性、脉冲剂量依赖性、在Cyberknife和TrueBeam光子束中评价了MSX的剂量-响应线性，并与包括microDiamond在内的各种探测器进行了比较（PTW型号60019：MD），Sun Nuclear EDGE探测器，光子二极管（PTW型号60016：PD）和半折电离室结果对于50 x 50 mm（2）至400 x 400 mm（2）的射野尺寸，MSX测量的OFdet值在IC测量值的1%范围内。对于射波刀小射野，MSX测量的OFdet和MD测量的射野输出因子（Ω）之间的最大差异为4.0%，而PD和EDGE的最大差异分别为8.8%和10.9%。MSX在5 ℃至34 ℃的水温范围内显示出0.7%的稳定响应，而PD和EDGE显示出水温与响应之间的线性相关性。MSX显示剂量率在0.2%内的小变化，PD和EDGE显示响应随剂量率呈对数增加。MSX和MD对DPP的依赖性小于PD和EDGE。结论MSX对小场和大场光子束测量的特性是有利的。与PD相比，MSX在小视场的过响应方面表现出显着的改善。通过MSX测量的OFdet值大约在通过MD和PD测量的值之间。MSX对水温，剂量率和DPP变化表现出稳定的反应，并提供了适合的数据范围广泛的字段大小。然而，对于= 200 x 200 mm（2）的场尺寸，需要仔细注意OFdet的测量。
Purpose This study investigated the characteristics of a new shielded diode detector, microSilicon X (model 60022: MSX), for small-field and large-field dosimetry.Methods The percent depth dose (PDD), beam profiles, detector output factor (OFdet), temperature dependence, dose rate dependence, dose-per-pulse (DPP) dependence, and dose-response linearity of MSX were evaluated in Cyberknife and TrueBeam photon beams and compared with various detectors including microDiamond (PTW model 60019: MD), Sun Nuclear EDGE detector, Photon diode (PTW model 60016: PD), and semiflex ionization chamber (PTW model 31010: IC).Results For field sizes ranging from 50 x 50 mm(2) to 400 x 400 mm(2), MSX-measured OFdet values were within 1% of the IC-measured values. For the CyberKnife small fields, the maximum difference between the MSX-measured OFdet and the MD-measured field output factor (omega) was 4.0%, while the maximum differences were 8.8% and 10.9% for PD and EDGE, respectively. MSX showed a stable response within 0.7% for water temperatures of 5 degrees C to 34 degrees C, while PD and EDGE showed a linear correlation between the water temperature and the response. MSX showed small variations within 0.2% for the dose rate, and PD and EDGE showed logarithmic increases in the response with the dose rate. MSX and MD had smaller DPP dependences than PD and EDGE.Conclusions The characteristics of MSX for measurements of small- and large-field photon beams are favorable. Compared to PD, MSX exhibited significant improvement in the over-response for small fields. The OFdet values measured by MSX were approximately in-between those measured by MD and PD. MSX showed stable responses against water temperature, dose rate, and DPP variations and provided suitable data for a wide range of field sizes. However, careful attention is required for measurements of OFdet for field sizes of = 200 x 200 mm(2).