1 Department of Experimental Clinical Oncology, Faculty of Health Sciences, Aarhus University, Aarhus University2 Institute of Nuclear Physics, Polish Academy of Science, Kraków3 Division of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg4 Institute of Physics, Jagiellonian University, Kraków5 Department of Physics and Astronomy, Science and Technology, Aarhus University6 Centre of Oncology, Kraków, Poland7 Department of Physics and Astronomy, Science and Technology, Aarhus University
Introduction: Predictions of the radiobiological effectiveness (RBE) play an essential role in treatment planning with heavy charged particles. Amorphous track models (  ,  , also referred to as track structure models) provide currently the most suitable description of cell survival under ion irradiation. The aim of this paper is to compare the predictions from different amorphous approaches found in the literature - more specifically the phenomenological, analytical model by Katz and co-workers  and a Monte-Carlo based full as implemented for example in the local effect model by Scholz et al.  . In addition, a new approach based on microdosimetric distributions is presented and investigated  . Material and methods: A suitable software library embrasing the mentioned amorphous track models including numerous submodels with respect to delta-electron range models, radial dose distribution models, and gamma response models was developed. This software can be used for direct numerical comparison between the models, submodels and their parameters and experimental data. In the present paper, we look at 10%-survival data from cell lines irradiated in vitro with carbon and proton beams by Tsuruoka et al.  . Results and conclusion: Preliminary results show a good agreement of models predictions and the experimental data for clinical doses. When investigating the influence of radial dose distributions on inactivation cross section in the Katz model, we found that one of the most important factors is the normalization of the energy distribution around the particle tracks to the actual LET value. Later on we check what is the effect of radial dose distribution choice on kappa parameter for different types and energy of ions. Outline References 1.Katz R, Sharma SC.Response of cells to fast neutrons, stopped pions, and heavy ion beams. Nucl Instrum Meth. 1973;111:93-116. 2.Weyrather WK, Kraft G. RBE of carbon ions: experimental data and the strategy of RBE calculation for treatment planning. Radiother Oncol. 2004;73(Suppl 2):161-9. 3.Greilich S, Grzanka L, Bassler N, Andersen CE, Jäkel O. Amorphous track modelling of luminescence detector efficiency in proton and carbon beams. 4.Tsuruoka C, Suzuki M, Kanai T, et al. LET and ion species dependence for cell killing in normal human skin fibroblasts. Radiat Res. 2005;163:494-500.