Ce:LaB3O6 glass for high-resolution radiation dosimetry

Ce:LaB3O6 (LBO) glass, whose constituents are abundant elements and fabrication is easy and cheap, is found to be a promising thermoluminescence (TL) dosimeter. This is originally achieved by CeF3 doping and melting under a reducing atmosphere, with the optimum concentration of 0.1% (quantum efficiency = 66%). The corresponding Ce interatomic distance is ~ 4 nm, below which concentration quenching occurs via Ce dipole-dipole interaction, as elucidated experimentally by Dexter’s theory. Ce:LBO exhibits a good dose resolution, with a linear dependence covering five orders of magnitude on both irradiation-dose and TL-response. Furthermore, it can be cyclically irradiated and read without degradation.

Evaluation of rare-earth sesquioxides nanoparticles as a bottom-up strategy toward the formation of functional structures

Background: The strategy to form functional structures based on powder technology relies on the concept of nanoparticles characteristics. Rare-earth sesquioxides (RE2O3; RE as Y, Tm, Eu) exhibit remarkable properties, and their fields of application cover energy, astronomy, environmental, medical, information technology, industry, and materials science. The purpose of this paper is to evaluate the RE2O3 nanoparticles characteristics as a bottom-up strategy to form functional materials for radiation dosimetry. Methods: The RE2O3 nanoparticles were characterized by the following techniques: XRD, SEM, PCS, FTIR, ICP, EPR, and zeta potential. Results: All RE2O3 samples exhibited cubic C-type structure in accordance with the sesquioxide diagram, chemical composition over 99.9%, monomodal mean particle size distribution, in which (d50) was inferior than 130nm. Among all samples, only yttrium oxide exhibited EPR signal, in which the most intense peak was recorded at 358mT and g 1.9701. Conclusion: The evaluation of nanoparticle characteristics is extremely important taking into account a bottom-up strategy to form functional materials. The RE2O3 nanoparticles exhibited promising characteristics for application in radiation dosimetry.

Whole-body biodistribution and radiation dosimetry of [18F]PR04.MZ: a new PET radiotracer for clinical management of patients with movement disorders

Purpose [18F]PR04.MZ is a new PET imaging agent for dopamine transporters, providing excellent image quality and allowing for the evaluation of patients with movement disorders such as Parkinson’s disease. The objective of this study was to evaluate the biodistribution and radiation dosimetry of [18F]PR04.MZ by serial PET imaging. Methods Six healthy subjects (n = 3 males, n = 3 females) were enrolled in this study. A series of 14 whole-body PET/CT scans were acquired until 5.5 h post-injection of 200 ± 11 MBq of [18F]PR04.MZ. After rigid co-registration, volumes of interest were outlined either on CT or PET images. Time-integrated activity coefficients were calculated for selected source organs. Organ absorbed doses, and the effective dose were calculated using IDAC-Dose 2.1. Results Physiological uptake of [18F]PR04.MZ was mainly observed in the striatum, brain, liver, gall bladder, intestine, red marrow and cortical bone. [18F]PR04.MZ was primarily excreted via hepatobiliary clearance and, to a lower extent, via renal clearance. The normalized absorbed doses were highest in gall bladder wall (32.2 ± 6.4 µGy/MBq), urinary bladder wall (27.2 ± 4.5 µGy/MBq), red marrow (26.5 ± 1.4 µGy/MBq), cortical bone surface (26.3 ± 2.5 µGy/MBq), liver (22.5 ± 1.8 µGy/MBq) and kidneys (21.8 ± 1.1 µGy/MBq). The effective dose according to ICRP 60 and 103 was 16.3 ± 1.1 and 16.6 ± 1.5 µSv/MBq, respectively. Conclusion [18F]PR04.MZ has a favourable dosimetry profile, comparable to those of other 18F-labelled PET tracers, and is suitable for larger clinical applications. Trial registration CEC SSM Oriente, Santiago, Chile, permit 20140520.

Investigation of X-ray Radiation Detectability Using Fabricated ZnO-PB Based Extended Gate Field-Effect Transistor as X-ray Dosimeters

A new design of the MOSFET dosimeter is being developed in a different study to measure the dose delivered to the tissue layers. Development of zinc oxide-Lead (ZnO-Pb) of different thicknesses fabricated by chemical bath deposition were investigated to study their sensitivity following irradiation using a low absorbed dose that can be used in diagnostic and interventional radiology (9, 36.5, and 70 mGy) and high absorbed dose (1, 5, and 10 Gy) of X-ray. The morphology and structure of the as-prepared films were analysed using FESEM and XRD measurements. The device relies on sensing the changes in the local electric field arising from radiation interactions in the absorber, coupled with the semiconductor materials used in this work—ZnO-Pb as the EGFET. Then the sensitivity of all devices was examined. Generally, thin-film devices showed less sensitivity to X-ray than the disk type. The sensitivity of the thin film dropped from 6.66 mV/to 1.42 mV/Gy, while the sensitivity of the ZnO-Pb disk type was 23.3 mV/Gy, which then dropped to 6.30 6.42 mV/Gy. Furthermore, the disk type ZnO-Pb was exposed to a high absorbed dose and obtained a sensitivity value of 0.08 mV/Gy, while the ZnO-Pb thin film obtained 0.01 mV/Gy. This can be related to the influence of thickness on the sensitivity of the dosimeter. However, the device’s performance characteristics, like sensitivity to radiation exposure and operating dose area, were discovered to be strongly dependent on the materials employed, effective atomic number, and thickness of the materials. Based on the results shown above, these devices might be considered a low-cost candidate for real-time -radiation dosimetry at room temperature. Furthermore, the thickest sample of 1 mm showed better sensitivity to radiation, compared to the thinner samples.