Physics in Medicine & Biology
Jul 2, 2012
Dose to tissue medium or water cavities as surrogate for the dose to cell nuclei at brachytherapy photon energies
Shirin A Enger, Anders Ahnesjö, Frank Verhaegen and Luc Beaulieu 2012 Phys. Med. Biol. 57 4489
Assuming that the cell nucleus with its DNA content is the most important target for biological response, the aim of this study was to investigate, by means of Monte Carlo (MC) simulations, the relationship of the dose to a cell nucleus in a medium, MC-Dn,m, to dose to the local medium, MC-Dm,m, and dose to a water cavity embedded in the medium, MC-Dw,m. This was carried out for different combinations of cell nucleus compositions and tissue media, for different photon energies used in brachytherapy and compared to cavity theory calculated Dw,m. Our results showed that for the nucleus compositions and tissue types investigated, MC-Dw,m is a good substitute to MC-Dn,m. Whether other studied surrogates are good approximations to MC-Dn,m depends on the target size, target composition, composition of the surrounding tissue and photon energy. Elemental compositions of the tissue and nuclei affect considerably the absorbed dose to the cell nuclei for low energy brachytherapy sources.
About the author
Shirin A Enger (Université Laval, Québec, Canada), Anders Ahnesjö (Uppsala University and Elekta Instrument AB, Uppsala, Sweden), Frank Verhaegen (Maastricht University Medical Center, the Netherlands and McGill University, Montréal, Québec, Canada) and Luc Beaulieu (Université Laval, Québec, Canada)