Monte Carlo simulation and polymer gel dosimetry of 60 MeV clinical proton beams for the treatment of ocular tumours.

Monte Carlo (MCNPX) simulations of a clinical proton beam-line under a range of beam conditions have been compared with MR analysis of irradiated polymer gel (BANG-1). Gel results were found to under-estimate the height of the full energy Bragg peak relative to simulation by the order of 30%, due to increased LET in this region, which has been reported elsewhere. Comparison of narrow-beam lateral profiles suggests a slight over-prediction of lateral proton scatter in MCNPX, which has been reported previously.