Monte Carlo and experimental internal radionuclide dosimetry in RANDO head phantom

Abstract

Monte Carlo techniques are widely employed in internal dosimetry to obtain better estimates of absorbed dose distributions from irradiation sources in medicine. Accurate 3D absorbed dosimetry would be useful for risk assessment of inducing deterministic and stochastic biological effects for both therapeutic and diagnostic radiopharmaceuticals in nuclear medicine. The goal of this study was to experimentally evaluate the use of Geant4 application for tomographic emission (GATE) Monte Carlo package for 3D internal dosimetry using the head portion of the RANDO phantom. GATE package (version 6.1) was used to create a voxel model of a human head phantom from computed tomography (CT) images. Matrix dimensions consisted of 319 × 216 × 30 voxels (0.7871 × 0.7871 × 5 mm(3)). Measurements were made using thermoluminescent dosimeters (TLD-100). One rod-shaped source with 94 MBq activity of (99m)Tc was positioned in the brain tissue of the posterior part of the human head phantom in slice number 2. The results of the simulation were compared with measured mean absorbed dose per cumulative activity (S value). Absorbed dose was also calculated for each slice of the digital model of the head phantom and dose volume histograms (DVHs) were computed to analyze the absolute and relative doses in each slice from the simulation data. The S-values calculated by GATE and TLD methods showed a significant correlation (correlation coefficient, r(2) ≥ 0.99, p < 0.05) with each other. The maximum relative percentage differences were ≤14% for most cases. DVHs demonstrated dose decrease along the direction of movement toward the lower slices of the head phantom. Based on the results obtained from GATE Monte Carlopackage it can be deduced that a complete dosimetry simulation study, from imaging to absorbed dose map calculation, is possible to execute in a single framework.

Estimation of Photon and Electron Specific Absorbed Fractions for Selected Organs of a Human Voxelizedphantom Using GATE Monte Carlo Package

“…The assessment of the curves plotted in Figure 3 also confirmed that the organ geometry (such as size and shape), density, and the inter-organ distance have a significant influence on the photon cross-irradiation SAF values (14).…”

Web of Science, Scopus, and Google Scholar citation rates: a case study of medical physics and biomedical engineering: what gets cited and what doesn’t?

“…MOSFET (14) Although several articles published in 2015 have received citations to date in Web of Science [13][14][15][16][17][18][19][20][21][22][23][24] or Scopus [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] it was considered insufficient time to represent citation trends of more mature articles amongst the various categories.…”

A metal-oxide-semiconductor radiation dosimeter with a thick and defect-rich oxide layer

“…Therefore, we usually need to detect the dose of radiation received by people or objects in areas such as space travel, medical care and environmental moni toring. Several kinds of dosimeters have been explored such as thermo luminescent dosimeters (TLDs) [2], semiconductor diodes [3] and optically stimulated luminescence dosimeters (OSDLs) [4]. However, most of them are not suitable for working in space, as they do not meet the requirements of being of low weight and small size, as well as able to work following exposure to high doses.…”