Medical Physics Seminar – Thursday, June 21, 2012
Macro-Step Monte Carlo Methods and Their Applications in Proton Radiotherapy and Optical Photon Transport
Dustin Jacqmin (student of Dr. T. Rockwell Mackie)
Research Assistant, Department of Medical Physics, UW-School of Medicine & Public Health, Madison, WI USA
SPECIAL SEMINAR, 9am in room 1309 HSLC
First developed in the 1990’s, macro Monte Carlo (MMC) methods have been implemented
and successfully applied to electron beam radiotherapy dose calculation. The purpose of
this thesis work was to apply the same MMC methods to proton radiotherapy dose calculation
and light propagation Monte Carlo simulations. First, the MMC method was implemented
for proton radiotherapy dose calculation. A database composed of pre-calculated
steps was created using MCNPX for many materials and beam energies. The database was
used by a custom proton MMC code called PMMC to transport protons through a heterogeneous
absorbing geometry. The PMMC code was tested against MCNPX for a number of
different proton beam energies and geometries and proved to be accurate and much
more efficient.
The MMC method was also implemented for light propagation Monte Carlo simulations.
The widely accepted Monte Carlo for multilayered media (MCML) was modified to incorporate
the MMC method. The original MCML uses basic scattering and absorption physics to
transport optical photons through multilayered geometries. The MMC version of MCML
was tested against the original MCML code using a number of different geometries and
proved to be just as accurate and more efficient. This work has the potential to accelerate
light modeling for both photodynamic therapy and near-infrared spectroscopic imaging.