​Numerical simulation is widely used to optimize and individualize conventional radiotherapy protocols (which uses photons to treat the tumor target). However, this approach suffers from a lack of precision for applications in hadrontherapy, a rapidly growing form of radiotherapy that uses beams of protons or carbon-12 ions: indeed, the codes conventionally used do not faithfully reproduce the hadron interactions in particle/matter collision processes.

GATE is a computational code developed in recent years, as part of the international OpenGATE collaboration involving researchers from the BioMaps laboratory (Service Hospitalier Frédéric-Joliot), to model medical imaging systems (nuclear imaging, X-ray radiography, optical imaging) and also radiotherapy. This open-source software helps to design new imaging devices, to optimize acquisition protocols, or to evaluate image reconstruction algorithms. It is also very powerful for dose calculation in radiotherapy experiments: it offers a calculation of particle/matter interactions by Monte-Carlo approach, allowing to reach a level of precision higher than the analytical techniques classically used for these applications. 

In an article published in Medical Physics, researchers describe and validate the use of GATE to simulate hadrontherapy treatments on the basis of real protocols carried out in 3 major European centres (Proton Imaging and Dose Calculation in Proton Therapy at the Centre Antoine Lacassagne, Nice, France and at the Christie NHS Foundation Trust, Manchester, UK; Proton and Carbon Ion Beam Dose Calculation at the MedAustron IonTherapy Centre, Wiener Neustadt, Austria). The applications presented use three completely different machines (manufacturers and technologies), which highlighted the versatility and applicability of the GATE platform in a clinical environment.

This new bridge between fundamental research in particle physics, numerical simulation, and the experience of therapists using light ion beams shows the relevance of the OpenGATE collaboration for the optimization of cancer radiotherapy protocols.

Estimation by GATE simulation of the dose distribution during treatment of a brain tumour with carbon-12 ion beams. Grevillot et al. 

Contact: 

Sébastien JAN (sebastien.jan@cea.fr) 

[1] Sébastien JAN, currently Deputy Director of the UMR BioMaps, was the scientific coordinator of the OpenGATE collaboration between 2003 and 2018.