ANALYTICAL AND MONTE CARLO SIMULATION STUDY OF THE INFLUENCE OFSTRONG MAGNETIC FIELDS ON THE PATH OF ELECTRONS WITH ENERGY TYPICAL OF MRI-LINAC RADIOTHERAPY

Both analytical and numerical methods have proven to be suitable for describing radiation transport and interactions. The standard Boltzmann formalism derived from statistical mechanics requires to be specifically re-formulated to account for the interactions with external electromagnetic fields. Verifying the proper implementation of the external electromagnetic field coupling in Monte Carlo simulation codes is a key issue to confirm the feasibility of using such a tool to describe complex applications like image-guided radiotherapy based on integrating magnetic resonance scanner to the radiant field of ionizing radiation along with the subsequent dosimetric effects. The present work reports on the feasibility and reliability of the Monte Carlo FLUKA and PENELOPE main codes to assess electron trajectory in presence of strong magnetic fields. The obtained results confirm the ability of FLUKA and Penelope to model the alterations in the electron trajectories due to external magnetic field effects, also demonstrating an excellent agreement between both codes and with the theoretical-analytical model.