A Monte Carlo study on the effects of a static uniform magnetic field on micro-scale dosimetry of Auger-emitters using Geant4-DNA

Abstract

In this work, an effort has been made to improve cellular dosimetry of Auger radionuclides through investigating any possible effect of an applied static uniform magnetic field (up to 10 T) on the absorbed doses of ionizing radiation in the micron-sized spherical volumes of liquid water per unit cumulated activity (S-values). The Geant4-DNA extension of the Geant4 Monte Carlo toolkit was employed to simulate the radioactive decay of several theranostic Auger-emitters, including 99mTc, 111In, 123I, 125I, and 201Tl which, distributed within various compartments of a typical spherical cell model. The S-values were calculated in the target regions belonging to both the cell containing the electron source (self-dose) and the second similar cell adjacent to it (cross-dose), with and without the presence of the magnetic field. The results related to the self- and cross-dose cases in the zero magnetic fields were compared to the corresponding MIRD ones. Based on the obtained results for the examined radionuclides and cell dimensions, it can be concluded that the self-dose values are not affected by a static uniform magnetic field, but the cross-dose ones increase slightly (up to 19%) depending on the orientation and strength of the magnetic field.