Evaluation of MCNP5 and EGS4 for the simulation of in-vivo strontium XRF measurements

In order to optimize x-ray fluorescence (XRF) experiments, Monte Carlo (MC) simulations provide a valuable tool that allows different system setups and experimental conditions to be explored in a controlled way. Electron gamma shower (EGS4) and Monte Carlo N-Particle5 (MCNP5) are two widely used MC programs that simulate the photon and electron transport in great detail and allow for the simulation of an arbitrary experimental geometry. Tested in 2001 by Al-Ghorabie et al.,1 earlier versions of these programs failed in reproducing the outcome of a platinum XRF in vivo measurement. The authors found that the discrepancy between measured and simulated results could be attributed to the free electron approximation made by the programs in simulating the Compton scattering. More recent versions of EGS4 and MCNP have updated their treatment for photon transport at low energies and have included Doppler broadening in the Compton profile. In this study we test the capability of these new versions of EGS4 and MCNP in reproducing the outcome of an in vivo strontium XRF measurement. Copyright © 2007 John Wiley & Sons, Ltd.