Optimization study of a medical phantom allowing the mapping of absorbed dose induced by ionizing radiations (original) (raw)

—Monte Carlo codes are among the most used tools for calculations and simulations relating to medical physics and particularly for studies of low dose medical applications. The results, presented in this paper, were focused on the optimization of a medical phantom for mapping the absorbed doses produced by ionizing radiation. The cobalt 60 irradiator of the CNSTN (the National Centre for Nuclear Science and Technology) served as the experimental validation platform for the present study. Monte-Carlo modeling of the irradiator was carried out with Geant4 tool. Part of dose deposition results, obtained with this model, has been validated using as reference previous experimental data, performed on the same irradiator. The same Geant4 model was then adapted to our study case, with the development of a more specific configuration, suitable for the diagnosis of the effects induced by gamma radiation beams at different energies. The distribution study of doses produced by these photons, inside a water filled phantom, was thus realized. The numerical results obtained, with the Geant4 model, show variable behaviours according to the studied energies. An analytical model is then proposed, for the prediction of these dose distributions.