Alpha-particle Monte Carlo simulation for microdosimetric calculations using a commercial spreadsheet.
Alpha-particle emitters are currently being evaluated in the treatment of cancer. Because of the short range and high linear energy transfer (LET) of most therapeutic alpha-particle emitters, there are significant stochastic variations in the energy deposited within the cellular nucleus. Hence microdosimetric spectra are often necessary to interpret biological endpoints. However, alpha-particle microdosimetric codes are not readily available. In this paper, we describe how a commercial spreadsheet may be used to perform a Monte Carlo simulation of alpha-particle transport. Subsequently, this information is used to determine the distribution of path lengths, energy deposited, and specific energy for a single alpha-particle traversal through the cell nucleus. These data may then be used to determine microdosimetric parameters for multiple alpha-particle emissions. In our analysis, comparison of the first and second moments of the single-event spectra with previously published data show agreement on the order of a few per cent. These small discrepancies are due to differences in interpolation of stopping powers between the various algorithms. Thus, the spreadsheet Monte Carlo method represents a simple and efficient method to calculate single-event spectra for alpha-particle emitters. Copies of the spreadsheet are available from the corresponding author upon request.
Roeske
John C
JC
Department of Radiation and Cellular Oncology, University of Chicago, 5758 S Maryland Ave., MC 9006, Chicago, IL 60637, USA. roeske@rover.bsd.uchicago.edu
Hoggarth
Mark
M
D000512:Alpha Particles; D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D003627:Data Interpretation, Statistical; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D018499:Linear Energy Transfer; D015233:Models, Statistical; D009010:Monte Carlo Method; D011381:Programming Languages; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods*; D011879:Radiotherapy Dosage; D012984:Software; D013269:Stochastic Processes