title: Radial dose distributions from carbon ions of therapeutic energies calculated with Geant4-DNA.
abstract: We report on radial dose distributions [Formula: see text] for carbon ions calculated with Geant4-DNA code. These distributions characterize ion tracks on a nanoscale and are important for understanding the biological effects of ion beams. We present data for carbon ion beams in the energy range from 20 to 400 MeV u-1. To approximate the Monte Carlo results, we developed a simple formula that combines the well-known inverse square distance dependence with a factor correcting [Formula: see text] for small [Formula: see text]. The proposed formula can be used to calculate [Formula: see text] for any energy within the above range and for distances [Formula: see text] from 1 nm to 2 μm with a maximum error not exceeding 14%. This range of distances corresponds to a dose range of over seven orders of magnitude. Differences between our results and those of previously published analytical models are discussed.
authors.affiliation: Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, United States of America.
authors.forename: He
authors.initials: H
authors.lastname: Wang
authors.forename: Oleg N
authors.initials: ON
authors.lastname: Vassiliev
mesh_terms: D063193:Heavy Ion Radiotherapy / Q000379:methods*; D009010:Monte Carlo Method; D011829:Radiation Dosage; D011879:Radiotherapy Dosage