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Patient-Specific Dose Assessment Using Cbct Images and Monte Carlo Calculations Publisher



Aghaz A1 ; Kardan MR1 ; Deevband MR2 ; Bahadorzadeh B3 ; Kasesaz Y1 ; Ghadiri H4
Authors
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Authors Affiliations
  1. 1. Reactor and Nuclear Safety Research School, Nuclear Science and Technology Research Institute (NSTRI), Tehran, Iran
  2. 2. Department of Medical Physics, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
  3. 3. Nuclear Engineering Department, Shiraz University, Shiraz, Fars, Iran
  4. 4. Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran

Source: Journal of Instrumentation Published:2021


Abstract

Today, the use of Cone-Beam Computed Tomography (CBCT) is increasing rapidly in medical diagnosis, therefore evaluation of patient's dose is a very important issue in radiation protection of patients. This study aimed to evaluate the patient-specific dose using CBCT images. Since CBCT images only showed a part of the head and while, the total anatomical specification of the head should be defined for dose assessment, therefore the whole parts of the head were generated using the data of the Extended Cardiac-Torso (XCAT) reference phantoms and pseudo-images were created. Tissue densities were calculated by the voxel values of pseudo-images and were used as the input file of Gate8.2 Monte Carlo (MC) code. Also, the GIANO CBCT unit was simulated and the absorbed dose was calculated by the code. For verification of this method, Rando phantom with embedded thermoluminescence dosimeters (TLD) with different protocols was used. The results of MC calculations and TLD measurements were compared and statistical analysis was performed using IBM SPSS Statistics. The calculated effective dose values determined by CBCT images for three different Temporomandibular joint, Single-Arch, and Both-Arch protocols were found to be 87 ± 3 μSv, 64 ± 1 μSv, and 66 ± 2 μSv, and the results of thermoluminescence dosimetry were 86 ± 2 μSv, 57 ± 1 μSv, and 63 ± 3 μSv, respectively. There were no significant differences (P-Value>0.05) between the results of MC calculations using CBCT images and the results of TLD dosimeters. In this study, a method for patient-specific dose assessment using CBCT images was introduced. It was shown that the dose of patients with its specification can be evaluated by CBCT images with acceptable accuracy. © 2021 IOP Publishing Ltd and Sissa Medialab.