Pérez Lara, Maria Laura;
(2025)
Development of a compact Compton camera using HEXITEC detectors for online treatment verification during particle therapy.
Doctoral thesis (Ph.D), UCL (University College London).
![]() |
Text
Perez Lara_10212762_Thesis_ID_removed.pdf Access restricted to UCL open access staff until 1 September 2026. Download (9MB) |
Abstract
Accurate in vivo verification remains a significant challenge in particle therapy. This work explores the potential of using pixellated semiconductor detectors as the core component of a compact Compton camera, designed for applications in Boron Neutron Capture Therapy (BNCT) and Proton Therapy (PT). BNCT is an emerging cancer treatment that targets tumour cells through the interaction of boron-enriched agents with (epi)thermal neutrons, while PT offers highly localised dose delivery that spares healthy tissue. In both modalities, secondary gamma particles are emitted from the patient, providing valuable spatial information on dose deposition. This research combines Monte Carlo simulations in Geant4 with experimental measurements using commercial HEXITEC detectors. The Stochastic Origin Ensemble (SOE) algorithm is used to reconstruct gamma origins, demonstrating successful imaging of both point and volumetric sources. The HEXITEC detector is shown to detect prompt gammas in complex radiation fields such as those found in PT, which can later be identified using post-processing algorithms like cluster size analysis and energy discrimination. Simulation studies indicate that a 3-layer HEXITEC configuration could enable verification for PT, while a 2-layer setup with commercial geometries shows promise for BNCT. Further Monte Carlo simulations in realistic BNCT and PT scenarios highlight the potential of the HEXITEC Compton camera and SOE algorithm for in vivo verification. Nonetheless, challenges remain in quantifying boron concentrations and dose from gamma counts in BNCT, and in optimising detection efficiency at PT energies. A first-generation Compton camera prototype was built and experimentally evaluated for spatial resolution and coincidence performance, although limitations in its triggering mechanism and detector synchronisation were found to significantly hinder reliable event pairing and image reconstruction. These findings lay the groundwork for future hardware improvements and highlight the need for integrated acquisition systems in high-resolution gamma imaging.
Type: | Thesis (Doctoral) |
---|---|
Qualification: | Ph.D |
Title: | Development of a compact Compton camera using HEXITEC detectors for online treatment verification during particle therapy |
Language: | English |
Additional information: | Copyright © The Author 2025. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
Keywords: | Proton therapy, Boron neutron capture therapy, In vivo verification, HEXITEC detector, Compton camera, Stochastic origin ensemble |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Med Phys and Biomedical Eng |
URI: | https://discovery.ucl.ac.uk/id/eprint/10212762 |
Archive Staff Only
![]() |
View Item |