Department of Integrated Health Science, Nagoya University Graduate School of Medicine, Japan.
Department of Molecular Imaging and Theranostics, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology (QST), Japan.
Appl Radiat Isot. 2021 Mar;169:109495. doi: 10.1016/j.apradiso.2020.109495. Epub 2020 Dec 13.
In alpha radionuclide therapy, an optical fiber-based alpha particle detector is a new tool that could possibly be employed for the direct detection of alpha particles in subjects. Thus, in the present study, we developed an optical fiber-based alpha particle detector. The alpha particle detector was made of a 1mm diameter, 10 cm long plastic double clad optical fiber drilled a 0.7 mm diameter, 2 mm depth open space at the one end of the fiber. Silver-doped zinc sulfide (ZnS (Ag)) was painted inside this open space to form a ZnS(Ag) small scintillation chamber. To conduct performance comparisons, we also developed a fiber detector using the same fiber in which a Ce-doped LuYSiO (LYSO(Ce)) scintillator with dimensions of 0.32 mm × 0.5 mm × 5 mm was inserted. Both fiber detectors were wrapped in aluminized Mylar and optically coupled to a position sensitive photomultiplier tube, before calculating the two-dimensional distributions, energy, and pulse shape spectra. For 5.5-MeV alpha particles, the ZnS(Ag) fiber detector produced ~ 5 times larger pulse heights and the count rate was ~2 times higher compared with those using the LYSO(Ce) fiber detector. For the maximum energy 2.28-MeV beta particles and 0.66-MeV gamma photons, the ZnS(Ag) fiber detector produced no counts, but it yielded small counts from natural alpha particles. Our results confirmed that the ZnS(Ag) fiber detector developed in this study could selectively detect alpha particles and it was insensitive to beta particles and gamma photons.
在α放射性核素治疗中，基于光纤的α粒子探测器是一种新工具，可能用于直接检测受检者体内的α粒子。因此，本研究中我们开发了一种基于光纤的α粒子探测器。α粒子探测器由一根直径 1mm、长 10cm 的塑料双包层光纤制成，在光纤的一端钻一个 0.7mm 直径、2mm 深的开口。在这个开口内涂有掺银的硫化锌（ZnS(Ag)），形成一个 ZnS(Ag)小闪烁室。为了进行性能比较，我们还使用相同光纤开发了一种光纤探测器，其中插入了尺寸为 0.32mm×0.5mm×5mm 的掺铈硅酸镥（LYSO(Ce)）闪烁体。两种光纤探测器都用镀铝聚酯薄膜包裹，并与位置灵敏光电倍增管光学耦合，然后计算二维分布、能量和脉冲形状谱。对于 5.5MeV 的α粒子，ZnS(Ag)光纤探测器产生的脉冲幅度约为使用 LYSO(Ce)光纤探测器的 5 倍，计数率约为后者的 2 倍。对于最大能量为 2.28MeV 的β粒子和 0.66MeV 的γ光子，ZnS(Ag)光纤探测器没有计数，但它会产生来自天然α粒子的小计数。我们的结果证实，本研究中开发的 ZnS(Ag)光纤探测器可以选择性地检测α粒子，对β粒子和γ光子不敏感。
