Assessment of MIRD data for internal dosimetry using the GATE Monte Carlo code

Abstract

GATE/GEANT is a Monte Carlo code dedicated to nuclear medicine that allows calculation of the dose to organs of voxel phantoms. On the other hand, MIRD is a well-developed system for estimation of the dose to human organs. In this study, results obtained from GATE/GEANT using Snyder phantom are compared to published MIRD data. For this, the mathematical Snyder phantom was discretized and converted to a digital phantom of 100 × 200 × 360 voxels. The activity was considered uniformly distributed within kidneys, liver, lungs, pancreas, spleen, and adrenals. The GATE/GEANT Monte Carlo code was used to calculate the dose to the organs of the phantom from mono-energetic photons of 10, 15, 20, 30, 50, 100, 200, 500, and 1000 keV. The dose was converted into specific absorbed fraction (SAF) and the results were compared to the corresponding published MIRD data. On average, there was a good correlation (r (2)>0.99) between the two series of data. However, the GATE/GEANT data were on average -0.16 ± 6.22% lower than the corresponding MIRD data for self-absorption. Self-absorption in the lungs was considerably higher in the MIRD compared to the GATE/GEANT data, for photon energies of 10-20 keV. As for cross-irradiation to other organs, the GATE/GEANT data were on average +1.5 ± 8.1% higher than the MIRD data, for photon energies of 50-1000 keV. For photon energies of 10-30 keV, the relative difference was +7.5 ± 67%. It turned out that the agreement between the GATE/GEANT and the MIRD data depended upon absolute SAF values and photon energy. For 10-30 keV photons, where the absolute SAF values were small, the uncertainty was high and the effect of cross-section prominent, and there was no agreement between the GATE/GEANT results and the MIRD data. However, for photons of 50-1,000 keV, the bias was negligible and the agreement was acceptable.

A review of the use and potential of the GATE Monte Carlo simulation code for radiation therapy and dosimetry applications

“…In Ref. 62, GATE was used to compute specific absorbed fractions (SAF) for photon sources in selected organs of a reference anthropomorphic model. The Snyder mathematical model 63 was digitized and sampled (2 × 2 × 3 mm) to generate GATE input files for photons (10 keV to 1 MeV).…”

Monte Carlo and experimental internal radionuclide dosimetry in RANDO head phantom

“…Several studies have assessed the applicability of the GATE Monte Carlo package for internal dosimetry of radionuclides and related applications [3,4,20,21]. A brief summary of these studies can be found in a published review by Sarrut et al [22].…”

“…Each organ in the Zubal phantom has a unique code that identifies its voxels. This phantom has previously been used for internal dosimetry calculations with GATE/Geant4 Monte Carlo package and verified with MCNP4C data [3,4]. Otoko [5], ADELAIDE [6] and Golem [7] are similar examples of computational human models that have been constructed from CT scans of actual patients.…”

Assessment of the Absorbed Dose in the Kidney of Nuclear Nephrology Paediatric Patients using ICRP Biokinetic Data and Monte Carlo Simulations with Mass-Scaled Paediatric Voxel Phantoms

“…Zankl et al 13 report that, when comparing calculations using voxel phantoms with calculations using stylized ("MIRD-type") phantoms, deviations between 50% and 100% can be obtained. And finally, Hadid et al 14,15 and Parach et al 16 reach similar conclusions, showing that when calculating dose coefficients with voxel phantoms and comparing them with a MIRD phantom, significant variations (up to few hundred percent) were obtained.…”