An ERC Starting Grant developing prompt gamma time imaging, detector instrumentation and reconstruction methods. Secondary radiation signals are used to estimate particle range, tissue properties and dose, providing quantitative measurements for adaptive irradiation research.
Project abstract
Particle Therapy (PT) is potentially the most conformal and selective form of radiotherapy, but its clinical outcome is still limited, mainly because of the numerous sources of uncertainties affecting both treatment planning and delivery. The objective technical complexity of predicting and verifying the ion path in the patient has led to conservative treatm…Read the full abstractCollapse abstract
Particle Therapy (PT) is potentially the most conformal and selective form of radiotherapy, but its clinical outcome is still limited, mainly because of the numerous sources of uncertainties affecting both treatment planning and delivery. The objective technical complexity of predicting and verifying the ion path in the patient has led to conservative treatments that, in order to increase safety, sacrifice efficacy. Having the full control of the dose gradient within the patient in real time would allow to fully exploit the ballistic advantage of PT. The healthy-tissue sparing effect can be enormous, further encouraging the use of PT for paediatric malignancies. Alternatively, the target dose could be increased to achieve better tumour control, and dose escalation procedures could be envisaged to treat radio-resistant tumours. With the aim of increasing both safety and efficacy, I propose a new medical-imaging modality to monitor PT treatments in real-time. It exploits the signal of secondary prompt gamma-rays emitted from nuclear interactions in the patients to recover information on ion range, tissue density and dose. I refer to this technique as Prompt Gamma Time Imaging (PGTI). An original reconstruction algorithm and a dedicated detector will be developed to prove the clinical advantages of PGTI, and bring this technique at the doorsteps of its clinical application. I will develop models to correlate the images provided by PGTI to real-time dose distributions, in order to enable the use of this technique for adaptive dosimetry. PGTI will be also explored as a potential approach to proton tomography. For the first time, it would be possible to control the uncertainties affecting both treatment planning and treatment delivery with a unique device. PGTI may be the missing step towards the birth of image-guided particle therapy.
Research connections
Publications
2026
arXiv
Prompt-gamma (PG) imaging is a promising approach for in vivo verification in proton therapy, but existing methods are primarily limited to reconstructing the PG emission profile, which provides only indirect information on proton transport. In this work, we introduce Prompt-Gamma Time Imaging (PGTI), an iterative reconstruction method based on the PG Timing…Read the full abstractCollapse abstract
Prompt-gamma (PG) imaging is a promising approach for in vivo verification in proton therapy, but existing methods are primarily limited to reconstructing the PG emission profile, which provides only indirect information on proton transport. In this work, we introduce Prompt-Gamma Time Imaging (PGTI), an iterative reconstruction method based on the PG Timing (PGT) technique that jointly estimates the PG emission distribution and the proton velocity profile from Time-Of-Flight (TOF) measurements acquired with multiple detector modules. Unlike the PG distribution, the proton velocity is directly related to the stopping power and therefore provides access to both the tissue composition traversed by the beam and a first-order estimation of the delivered dose. The method was validated using experimental data acquired with the eight-module TIARA prototype previously developed by our collaboration. The anthropomorphic RANDO head phantom was irradiated with 100 MeV protons in two anatomical configurations representative of treatment planning and delivery, providing the first demonstration of PGTI under realistic conditions. In this example, the reconstructed material sequence agreed with the reference CT; despite ten bins presenting a misclassified material, the reconstructed proton range only differed from the expected value by approximately 1 mm. These results validate both the proposed PGTI framework and the use of the TIARA detector system in a pseudo-clinical environment, extending PG imaging beyond conventional range verification.