Integration and validation of the Geant4-DNA physical models into GATE simulation platform

Abstract

GATE (Geant4 Application for Tomographic Emission) is an open-source Monte-Carlo simulation platform based on Geant4 (GEometry And Tracking) simulation toolkit, widely used for many medical physics applications. Since the Geant4-DNA physical models have been integrated into the version GATE v7.0, the applications of GATE are extended to the field of radiobiology. The latest version GATE v7.2 is based on the Geant4.10.02.p01 version. However, the new Geant4-DNA Physics List with different options (opt1, opt2, opt3, opt4, opt5) of the Geant4.10.02.p01 version have not been incorporated in GATE v7.2; therefore we implemented the integration of the new Geant4-DNA Physics Lists into GATE v7.3-beta based on Geant4.10.02.p01. Also, we combined two different Physics List (Mixed Physics List) in GATE v7.3-beta which can be used in the same simulation. GATE v7.3-beta is a version of GATE that we developed in our work. In order to validate and verify the correct implementation of the Geant4-DNA physical models into GATE v7.3-beta, we used two benchmarks : DPKs (Dose Point Kernels) of 50000 particles of 10 keV electron point source in spherical water phantom with the diameter of 400 mm; and Example_DNA for 3000 particles of 8 MeV proton point source in three different targets made of liquid water with the thickness of 50 pm. A good agreement is found for the DPK calculation in case of 10 keV electrons where differences for eighteen shells are below 5 % between GATE and Geant4.10.02. The conclusions are : the validation of Geant4-DNA physical models by comparing of GATE v7.3-beta DPKs with Geant4.10.02.p01 and EGSnrc, the spectrum of the secondary electrons generated in three targets demonstrated the successful operation of the new Mixed Physics List in GATE v7.3-beta.