Tho Daline, Beddar Sam
Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
Medical Physics Program, The University of Texas MD Anderson Cancer Center UTHealth Houston Graduate School of Biomedical Sciences, Houston, TX 77030, USA.
Sensors (Basel). 2024 Dec 18;24(24):8064. doi: 10.3390/s24248064.
(1) Background: Ultra-high dose rate (UHDR) radiation therapy needs a reliable dosimetry solution and scintillation detectors are promising candidates. In this study, we characterized an inorganic powder-based scintillation detector under a 9 MeV UHDR electron beam. (2) Methods: A mixture of ZnS:Ag powder and optic glue was coupled to an 8 m Eska GH-4001-P polymethyl methacrylate (PMMA) optical fiber. We evaluated the dependence of the detector on dose per pulse (DPP), pulse repetition frequency (PRF), and pulse width (PW). Additionally, we determined the stability and the reproducibility of the detector. (3) Results: The signal ratio between the PMMA clear optical fiber and the ZnS:Ag scintillator was around 210. ZnS:Ag produced a signal yield 54 times greater than that of a BCF-12 plastic scintillator. Signal variation with PRF changes was under 0.5%. The signal was linear to the integrated dose up to the maximum deliverable dose, 180 Gy. The variation in signal was linear to the change in both PW and DPP. Regarding stability, the standard deviation of 10 consecutive irradiations was 0.83%. For the reproducibility, all daily measurements varied within ±1.5%. (4) Conclusions: These findings show that the ZnS:Ag detector can be used for accurate dosimetry with UHDR beams.
(1) 背景：超高剂量率（UHDR）放射治疗需要可靠的剂量测定解决方案，闪烁探测器是很有前景的候选者。在本研究中，我们对一种基于无机粉末的闪烁探测器在9 MeV超高剂量率电子束下的性能进行了表征。(2) 方法：将ZnS:Ag粉末与光学胶水的混合物耦合到一根8 m长的Eska GH - 4001 - P聚甲基丙烯酸甲酯（PMMA）光纤上。我们评估了探测器对每脉冲剂量（DPP）、脉冲重复频率（PRF）和脉冲宽度（PW）的依赖性。此外，我们还测定了探测器的稳定性和可重复性。(3) 结果：PMMA透明光纤与ZnS:Ag闪烁体之间的信号比约为210。ZnS:Ag产生的信号产额比BCF - 12塑料闪烁体高54倍。随着PRF变化的信号变化小于0.5%。在高达最大可输送剂量180 Gy的范围内，信号与累积剂量呈线性关系。信号变化与PW和DPP的变化均呈线性关系。关于稳定性，连续10次照射的标准偏差为0.83%。对于可重复性，所有日常测量值的变化在±1.5%以内。(4) 结论：这些发现表明，ZnS:Ag探测器可用于超高剂量率束流的精确剂量测定。
