A Novel Dosimetry System for Computed Tomography using Phototransistor
نویسندگان
چکیده
Computed tomography (CT) dosimetry normally uses an ionization chamber 100 mm long to estimate the computed tomography dose index (CTDI), however some reports have already indicated that small devices could replace the long ion chamber to improve quality assurance procedures in CT dosimetry. This paper presents a novel dosimetry system based in a commercial phototransistor evaluated for CT dosimetry. Three detector configurations were developed for this system: with a single, two and four devices. Dose profile measurements were obtained with them and their angular response were evaluated. The results showed that the novel dosimetry system with the phototransistor could be an alternative for CT dosimetry. It allows to obtain the CT dose profile in details and also to estimate the CTDI in longer length than the 100 mm pencil chamber. The angular response showed that the one device detector configuration is the most adequate among the three configurations analyzed in this study. Keywords—Computed tomography, dosimetry, photo-transistor
منابع مشابه
Characterization of Three Photodetector Types for Computed Tomography Dosimetry
In this study three commercial semiconductor devices were characterized in the laboratory for computed tomography dosimetry: one photodiode and two phototransistors. It was evaluated four responses to the irradiation: dose linearity, energy dependence, angular dependence and loss of sensitivity after X ray exposure. The results showed that the three devices have proportional response with the a...
متن کاملSiemens primus accelerator simulation using EGSnrc Monte Carlo code and gel dosimetry validation with optical computed tomography system by EGSnrc code
Monte Carlo method is the most accurate method for simulation of radiation therapy equipment. The linear accelerators (linac) are currently the most widely used machines in radiation therapy centers. Monte Carlo modeling of the Siemens Primus linear accelerator in 6 MeV beams was used. Square field size of 10 × 10 cm2 produced by the jaws was compared with TLD. Head simulation of Siemens accele...
متن کاملDevelopment of an Advanced Optical Coherence Tomography System for Radiation Dosimetry
Introduction: According to the literature, optical coherence tomography (OCT) can be used measure radiation absorbed dose. This study was carried out to design a computed tomography system for the calculation of absorbed dose and optimization of dose delivery in radiotherapy using gel dosimeters. Material and Methods: An advanced charge-coupled device based OCT system was developed in laborator...
متن کاملDevelopment of a Liver Phantom Based on Computed Tomography Images for Dosimetric Purpose
Introduction: The present study was conducted with the aim of designing a liver phantom for dosimetry. To benchmark the results obtained by the developed liver phantom, another method was applied for the dosimetry of a real liver tissue using imaging. Materials and Methods: For the purpose of the study, a real liver tissue was converted into a phantom based on thegram-molecular weight of the co...
متن کاملImpact of Photon Spectra on the Sensitivity of Polymer Gel Dosimetry by X-Ray Computed Tomography
Introduction: The purpose of the current study was to investigate the effect of X-ray spectra on the sensitivity of a polymer gel dosimeter imaged with a conventional computed tomography (CT) scanner. Material and Methods: The whole process of CT imaging of an irradiated polymer gel was simulated by MCNPX Monte Carlo (MC) code. The imaging of polyacrylamide gel was accomplished by means of a co...
متن کامل