Simulation of DNA damage clustering after proton irradiation using an adapted DBSCAN algorithm

In this work the Density Based Spatial Clustering of Applications with Noise (DBSCAN) algorithm was adapted to early stage DNA damage clustering calculations. The resulting algorithm takes into account the distribution of energy deposit induced by ionising particles and a damage probability function that depends on the total energy deposit amount. Proton track simulations were carried out in small micrometric volumes representing small DNA containments. The algorithm was used to determine the damage concentration clusters and thus to deduce the DSB/SSB ratios created by protons between 500 key and 50 MeV. The obtained results are compared to other calculations and to available experimental data of fibroblast and plasmid cells irradiations, both extracted from literature. (C) 2010 Elsevier Ireland Ltd. All rights reserved.