Oertli, David Bernhardt (2006-08). Proton dose assessment to the human eye using Monte Carlo n-particle transport code (MCNPX). Master's Thesis. Thesis uri icon

abstract

  • The objective of this project was to develop a simple MCNPX model of the human eye to approximate dose delivered from proton therapy. The calculated dose included that due to proton interactions and secondary interactions, which included multiple coulombic energy scattering, elastic and inelastic scattering, and non-elastic nuclear reactions (i.e., the production of secondary particles). After benchmarking MCNPX with a known proton simulation, the proton therapy beam used at Laboratori Nazionali del Sud-INFN was modeled for simulation. A virtual water phantom was used and energy tallies were found to correspond with the direct measurements from the therapy beam in Italy. A simple eye model was constructed and combined with the proton beam to measure dose distributions. Two treatment simulations were considered. The first simulation was a typical treatment scenario-where dose was maximized to a tumor volume and minimized elsewhere. The second case was a worst case scenario to simulate a patient gazing directly into the treatment beam during therapy. Dose distributions for the typical treatment yielded what was expected, but the worst case scenario showed the bulk of dose deposited in the cornea and lens region. The study concluded that MCNPX is a capable platform for patient planning but laborious for programming multiple simulation configurations.
  • The objective of this project was to develop a simple MCNPX model of the
    human eye to approximate dose delivered from proton therapy. The calculated dose
    included that due to proton interactions and secondary interactions, which included
    multiple coulombic energy scattering, elastic and inelastic scattering, and non-elastic
    nuclear reactions (i.e., the production of secondary particles). After benchmarking
    MCNPX with a known proton simulation, the proton therapy beam used at Laboratori
    Nazionali del Sud-INFN was modeled for simulation. A virtual water phantom was used
    and energy tallies were found to correspond with the direct measurements from the
    therapy beam in Italy. A simple eye model was constructed and combined with the
    proton beam to measure dose distributions. Two treatment simulations were considered.
    The first simulation was a typical treatment scenario-where dose was maximized to a
    tumor volume and minimized elsewhere. The second case was a worst case scenario to
    simulate a patient gazing directly into the treatment beam during therapy. Dose
    distributions for the typical treatment yielded what was expected, but the worst case
    scenario showed the bulk of dose deposited in the cornea and lens region. The study
    concluded that MCNPX is a capable platform for patient planning but laborious for
    programming multiple simulation configurations.

publication date

  • August 2006