A novel approach to seamless simulations of compact hadron therapy systems for self-consistent evaluation of dosimetric and radiation protection quantities

Hadron therapy installations are evolving towards more compact systems that require higher-quality beams for advanced treatment modalities such as proton flash and arc therapy. Therefore the accurate modelling of present and next-generation systems poses new challenges where the simulations require both magnetic beam transport and particle-matter interactions. We present a novel approach to building simulations of beam delivery systems at a level suitable for clinical applications while seamlessly providing the computation of quantities relevant for beam dose deposition, radiation protection assessment, and shielding activation determination. A realistic model of the Ion Beam Applications (IBA) Proteus® One system is developed using Beam Delivery Simulation (BDSIM), based on Geant4, that uniquely allows simulation using a single model. Its validation against measured data is discussed in detail. The first results of self-consistent simulations for beam delivery and equivalent ambient dose are presented. The results show that our approach successfully models the complex interactions between the beam transport and its interactions with the system for relevant clinical scenarios at an acceptable computational cost.