Development and evaluation of multi-energy PbO dosimeter for quality assurance of image-guide radiation therapy devices

Abstract

In radiation therapy, accurate radiotherapy treatment plan (RTP) reproduction is necessary to optimize the clinical results. Thus, attempts have recently been made to ensure high RTP reproducibility using image-guide radiation therapy (IGRT) technology. However, the clinical use of digital X-ray equipment requires extended quality assurance (QA) for those devices, since the IGRT device quality determines the precision of intensity-modulated radiation therapy. The study described in this paper was focused on developing a multi-energy PbO dosimeter for IGRT device QA. The Schottky-type polycrystalline PbO dosimeter with a Au/PbO/ITO structure was evaluated by comparing its response coincidence, dose linearity, measurement reproducibility, linear attenuation coefficient, and percent depth dose with those of Si diode and standard ionization chamber dosimeters.

Development and evaluation of a thallium (I) bromide dosimeter for intracavitary radiotherapy quality assurance

“…Though TlBr showed fewer desirable characteristics than the diode, it satisfied the evaluation criteria of 1.5% of the RSD. The diode also showed similar results to the RSD values when measured at a photon energy of 6 MV [9].…”

“…However, silicon diode dosimeters have a disadvantage in that their sensitivity changes due to radiation damage [7,8]. Therefore, various candidate photoconductor materials, such as cadmium zinc telluride, mercuric iodide, and thallium (I) bromide (TlBr), have been studied as alternative radiation detectors [9,10]. Among these alternatives, TlBr has advantageous physical properties, such as high radiation absorption efficiency as well as a high effective atomic number (𝑍 eff = (81 + 35)/2 = 58), a high density (7.56 g/cm 3 ), and a large optical band gap (2.68 eV) [11].…”

“…Single crystalline materials exhibit excellent detection performance; however, optimising the manufacturing process requires significant resources and time. Alternatively, the particle-in-binder deposition method has a lower manufacturing cost because it is easily deposited on a large area and the production method is relatively simple [9]. Therefore, in this study, we evaluated the measurement performance of the polycrystalline TlBr dosimeter using an Ir-192 source to improve brachytherapy QA.…”

Development and evaluation of a monoxide-based flexible skin dosimeter for radiotherapy at photon energies

“…The linearity result was evaluated through the coe cient of determination (R 2 ) of the linear regression that irradiated radiation by gradually increasing the dose in 3, 10, 50, 100, 200, 300, and 400 MU under 50 MU/min conditions. The evaluation criteria for R 2 were not less than 0.9990 12,13 . The reproducibility and linearity results were analyzed to evaluate the stability of the signals and the possibility of developing a exible skin dosimeter.…”

Development and evaluation of a lead oxide flexible skin dosimeter with a silicon passive layer

“…In the field of radiation detectors, material research has been actively conducted through various detection principles. Among them, lead oxide (PbO), a photoconductor, has high atomic number (𝑍 Pb : 82, 𝑍 O : 8), high density (9.53 g/cm 3 ), and excellent physical properties for use as a radiation dosimeter [10][11][12][13]. In addition, PbO can easily be manufactured with a polycrystalline dosimeter using a binder by the PIB deposition method.…”