Intercomparision of Monte Carlo Radiation Transport Codes MCNPX, GEANT4, and FLUKA for Simulating Proton Radiotherapy of the Eye

Abstract

Monte Carlo simulations of an ocular treatment beam-line consisting of a nozzle and a water phantom were carried out using MCNPX, GEANT4, and FLUKA to compare the dosimetric accuracy and the simulation efficiency of the codes. Simulated central axis percent depth-dose profiles and cross-field dose profiles were compared with experimentally measured data for the comparison. Simulation speed was evaluated by comparing the number of proton histories simulated per second using each code. The results indicate that all the Monte Carlo transport codes calculate sufficiently accurate proton dose distributions in the eye and that the FLUKA transport code has the highest simulation efficiency.

Fig. 1

The geometry of the ocular nozzle and the water phantom used for the simulations in GEANT4 and FLUKA. The components of the nozzle (left to right) are listed in Table I.

Fig. 2

Central axis PDD profiles obtained from the simulations along with IC data (top) and their ratio with respect to IC data (bottom) for a range setting of 25 mm using the circular aperture.

Fig. 3

Cross-field dose profiles obtained from the simulations and the IC data (top) and their ratios (bottom) for the range setting of 25 mm using the circular aperture at a depth of 17.5 mm in the water phantom.