FRoG: A platform for rapid and robust clinical dose calculations in hadron therapy

Radiotherapy with protons and heavier ions landmarks a novel era in the field of high-precision cancer therapy. To identify patients most benefiting from this technologically demanding therapy, fast assessment of comparative treatment plans utilizing different ion species is urgently needed. Moreover, to overcome uncertainties of actual in-vivo physical dose distribution and biological effects elicited by different radiation qualities, development of a reliable high-throughput algorithm is required. To this end, we engineered a unique graphics processing unit (GPU) based software architecture allowing rapid and robust dose calculation. Fast dose Recalculation on GPU, FRoG, currently operates with four particle beams, i.e., raster-scanning proton, helium, carbon and oxygen ions. Designed to perform fast and accurate calculations for both physical and biophysical quantities, FRoG operates an advanced analytical pencil beam algorithm using parallelized procedures on a GPU. Clinicians and medical physicists can assess both dose and dose-averaged LET distributions for proton therapy (and eventually DRBE by applying variable RBE schemes) to further scrutinize plans for acceptance or potential re-planning purposes within minutes. In addition, various biological model predictions are readily accessible for heavy ion therapy, such as LEM and MKM. FRoG has been extensively benchmarked against gold standard Monte Carlo simulations and experimental data. Evaluating against commercial treatment planning systems demonstrates the strength of FRoG in better predicting dose distributions in complex clinical settings. A summary of the recent clinical investigations with FRoG will be presented.