title: Simulation of light ion induced DNA damage patterns.
abstract: The biophysical simulation code PARTRAC was extended by a module to handle ions heavier than alpha particles. Cross sections for ion-electron interactions were taken from He(++) ions of the same velocity and scaled by Z(eff(2))/4. Calculated linear energy transfer values, radial dose distributions and secondary electron spectra were found in agreement with experimental results. DNA damage due to irradiation of human fibroblast cells by several light ions from H to S was calculated for various energies complemented by 220 kV(p) X rays as reference radiation. With increasing linear energy transfer, the calculated total yield of double-strand breaks per dose showed saturation behaviour at about twice the value for reference radiation. When data analysis methods for experimental double-strand break yield determination were applied to the simulated DNA damage patterns, the two data sets were found in accord. The calculated patterns of DNA damage clusters were analysed on local and regional scale finding regional clusters in closer correlation to experimental cell inactivation data.
authors.affiliation: GSF-Institute of Radiation Protection, Neuherberg, Germany. friedland@gsf.de
authors.forename: Werner
authors.initials: W
authors.lastname: Friedland
authors.forename: Peter
authors.initials: P
authors.lastname: Jacob
authors.forename: Herwig G
authors.initials: HG
authors.lastname: Paretzke
authors.forename: Andrea
authors.initials: A
authors.lastname: Ottolenghi
authors.forename: Francesca
authors.initials: F
authors.lastname: Ballarini
authors.forename: Marco
authors.initials: M
authors.lastname: Liotta
mesh_terms: D002843:Chromatin / Q000737:chemistry* / Q000528:radiation effects*; D003198:Computer Simulation; D004247:DNA / Q000737:chemistry* / Q000528:radiation effects*; D004249:DNA Damage; D004307:Dose-Response Relationship, Radiation; D007477:Ions; D018499:Linear Energy Transfer; D008956:Models, Chemical; D008958:Models, Molecular; D011829:Radiation Dosage; D011839:Radiation, Ionizing
chemical_list: D002843:Chromatin; D007477:Ions; D004247:DNA