An image reconstruction framework for integrated mode proton radiography that combines 2D information from lateral cameras and a reprojection kernel derived from the Fermi-Eyges theory was developed. It was extensively validated through Monte Carlo simulations to demonstrate high image quality (contrast, resolution, quantitative accuracy). This has been disseminated at two international conferences (European Society for Radiotherapy and Oncology (ESTRO) 2022 Annual Meeting, The third ion imaging workshop in 2022).
In the meanwhile, an experimental setup was built at UCLH; its potential was demonstrated first at the PBT at University College London Hospitals and at Mayo Clinic Arizona, where state of the art imaging capabilities for an integrated mode imaging device were obtained. This has been disseminated to two international conferences: the ESTRO 2023 Annual Meeting as well as the Particle Therapy Co-Operative (PTCOG) 2023 annual meeting; a scientific publication on this topic is under review as of September 2023.
Following demonstration of imaging capabilities, the device was used to produce real time imaging of simple moving objects, towards a demonstration of real-time tracking. Most of this work has been performed since mid-2023 at UCLH and the Marburg Ion therapy Centre. The latter allowed us to also evaluate the performance with carbon ion beams rather than just protons. We demonstrated highly accurate tracking abilities and characterised motion artifacts that arise with proton imaging. These results are being disseminated at various international (the fourth ion imaging workshop) and national (the proton physics research and implementation group (PPRIG) 2023 annual meeting), and aim to further show those results at the PTCOG 2024 annual meeting.
The figure attached to the report shows a schematic of the device (a), the actual built device (b), raw data images (c), high quantitative accuracy to characterise proton beams (d), high spatial localisation accuracy (e), and selected examples of scanned objects with previous state of art (distal) and the current method (lateral), in figures (f) and (g).
The current action led to the successful obtention of various research grants at University College London. A UCL global engagement fund for north America was obtained to perform measurements in 2022 at Mayo Clinic Arizona and demonstrate cross-centre usage of our device. Furthermore, a UCL Devices & Diagnostics TIN Pilot Data Scheme was obtained to allow the purchase of more performant equipment for the built device. This was also followed by dissemination activities on the project on UCL’s website. A 2023 UCL Fellowship Incubator Scheme was also obtained to fund measurements at the Marburg Ion Therapy Centre. Finally, the work done over the past two years under the Marie-Slokodowska-Curie Individual Fellowship led to a successful application to a National Institute for Health and Care Research (NIHR) invention for innovation product development award (£561229) to further develop proton radiography for adaptive radiography and image guidance.
Over the course of the action, our group co-organised the 3rd ion imaging workshop in Munich in 2022, and are now the main organisers of the 4th ion imaging workshop that is held in London in October 2023, which helps solidifies UCL and UCLH’s position as leaders in image guidance for proton imaging.
