Interface for Exchanging Geometric Parameters in Geant4 Based Particle Therapy Simulation Framework

The particle therapy system simulation framework (PTSIM) is a Geant4 based Monte Carlo simulation software developed for radiation therapy. It has been continuously extending the functions to facilitate advanced researches in medical physics domain. Consequently, the PTSIM is used in many facilities for verification of treatment plans and quality assurances. In the PTSIM, various types of beam devices are provided as software components named “beam-modules”. The geometry is constructed using a class of the beam-module and the detail geometric parameters in the ASCII data format. This strategy contributed that allows the PTSIM users to easily find the beam-module from the categorized types of beam devices and to develop a rapid prototyping of treatment port in the simulation. However, radiation therapy facilities may introduce variants of existing beam-modules, that may require the implementation of a new class for the beam-module in the PTSIM. In order to respond to such requirements without any coding effort, the interface for the Geometry Description Markup Language (GDML) has been introduced in the PTSIM. The GDML is a specialized XML-based language for an application-independent persistent format. Therefore, it can describe a user-defined complex geometry and exchanging the geometry data file among different facilities. In addition, for the purpose of examining complex geometries, a new interface for the ParaView visualization software has been developed. The interface converts the geometry in the PTSIM to the structured points data in the VTK legacy format. This paper reports on the implementations and the usages of GDML and ParaView interfaces in the PTSIM.