title: A method to perform multi-scale Monte Carlo simulations in the clinical setting.
abstract: In order to model the track structure of clinical mega-voltage photon beams in a reasonable time, it is necessary to use a multi-scale approach incorporating a track-structure algorithm for the regions of interest and a condensed history algorithm for the rest of the geometry. This paper introduces a multi-scale Monte Carlo system, which is used to hand off particle trajectory information between the two algorithms. Since condensed history algorithms ignore electrons with energy below a fixed threshold and those electrons are important to the track structure on the micrometre scale, it is necessary to hand over all charged particles to the track-structure algorithm only in a volume that extends beyond the scoring volume. Additionally, the system is validated against experimental results for radio-isotope gamma spectra.
authors.affiliation: Department of Radiation Oncology, University of Colorado School of Medicine, Aurora, CO, USA joseph.lucido@ucdenver.edu.
authors.forename: Joseph John
authors.initials: JJ
authors.lastname: Lucido
authors.affiliation: Vancouver Cancer Centre, British Columbia Cancer Agency, Vancouver, BC, Canada.
authors.forename: I Antoniu
authors.initials: IA
authors.lastname: Popescu
authors.affiliation: Departament of Radiation Oncology, University of California-San Diego, La Jolla, CA, USA.
authors.forename: Vitali
authors.initials: V
authors.lastname: Moiseenko
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D004583:Electrons; D005720:Gamma Rays; D006801:Humans; D015233:Models, Statistical; D009010:Monte Carlo Method; D017785:Photons; D011874:Radiometry / Q000379:methods*