Proton dose assessment to the human eye using Monte Carlo n-particle transport code (MCNPX)

摘要

The objective of this project was to develop a simple MCNPX model of thehuman eye to approximate dose delivered from proton therapy. The calculated doseincluded that due to proton interactions and secondary interactions, which includedmultiple coulombic energy scattering, elastic and inelastic scattering, and non-elasticnuclear reactions (i.e., the production of secondary particles). After benchmarkingMCNPX with a known proton simulation, the proton therapy beam used at LaboratoriNazionali del Sud-INFN was modeled for simulation. A virtual water phantom was usedand energy tallies were found to correspond with the direct measurements from thetherapy beam in Italy. A simple eye model was constructed and combined with theproton beam to measure dose distributions. Two treatment simulations were considered.The first simulation was a typical treatment scenario-where dose was maximized to atumor volume and minimized elsewhere. The second case was a worst case scenario tosimulate a patient gazing directly into the treatment beam during therapy. Dosedistributions for the typical treatment yielded what was expected, but the worst casescenario showed the bulk of dose deposited in the cornea and lens region. The studyconcluded that MCNPX is a capable platform for patient planning but laborious forprogramming multiple simulation configurations.