SEMINARIO: Cherenkov detectors for gamma detection in proton range verification in proton therapy

Abstract:

Proton-based radiotherapy has the potential to be a highly effective cancer treatment modality with low toxicity levels in the healthy tissue surrounding the tumor. The lack of a technique that provides a verification measurement of the proton range is hindering the evolution of this modality, as significant clearance margins need to be included in the treatment plan. One of the proposed approaches for proton range verification (PRV) in proton therapy is using the prompt-gamma (PG) emitted along its track, which peak towards the Bragg Peak (BP) at the end of the range. In this seminar I will present a prompt-gamma detector based exclusively on the Cherenkov light emitted in a high-density, high-Z and transparent crystal, PbF2. While Cherenkov light in pure Cherenkov crystals has been used to determine the detection time of the PG, no previous study reports on using such signal to determine the interaction position in the crystal. I will present a gamma detector concept aimed at building a PRV that employs physical collimators for PG. I will present the benchtop characterization in the lab using a 228Th, which emits gammas with up to 2.6 MeV with different electronic readout strategies. I will conclude with preliminary data acquired at a proton beam with 67.5 MeV protons, that yield PG with energies between 1 MeV and 6 MeV of energy.

Bio: Gerard coursed his PhD in radiation detectors for medical imaging in 2015, in the Institut de Física d’Altes Energies (IFAE), part of the campus of Bellaterra of the Universitat Autònoma de Barcelona. Between 2015 and 2016 he was part of the detector development team at the Deutsches-Elektronen Synchrotron (DESY) in Hamburg, Germany, as a postdoctoral scholar. Right after he joined the Department of Biomedical Engineering of the University of California, Davis, were he stayed as a postdoc (2016-18), assistant project scientist (2018-2021), and professional researcher (2021-present). Since 2023 he also has an appointment as sta_ scientist at IFAE.