Ponente
Descripción
Boron Neutron Capture Therapy (BNCT) is an experimental form of radiotherapy that uses boron, injected to the patient within a target molecule that accumulates selectively in cancerous cells. This therapy exploits the large boron neutron capture cross-section to deliver a targeted dose from neutron irradiation. BNCT has shown great promise with the advent of accelerator-based technologies, which facilitate high-quality neutron beams in clinical environments [1].
One of the primary challenges in current BNCT is the accurate determination of the dose delivered to the patient. The state-of-the-art method uses simple extrapolations from previous PET scans and online monitoring of boron concentration in blood. Since neutron captures in boron produce 478 keV gamma rays, this radiation could be potentially used for real-time dose monitoring. To date, the main challenges remain dealing with very intense radiation fields that generate large count rates above detector reach; and in achieving enough boron sensitivity to image the boron in the tumor (65 ppm) above the overall boron in nearby tissues (18 ppm), on top of the strong background induced by harsh neutron and gamma ray fields generated during the treatments; while attaining the spatial resolution required and moving towards true online capabilities during treatment.
The i-TED Compton Camera array, originally designed for nuclear physics measurements of astrophysics interest, has expanded into medical physics through ion-range monitoring in HT [2], and further aiming now at BNCT [3]. Its large efficiency design and low neutron sensitivity make i-TED especially well suited for this task.
This contribution will present the adaptations of the original i-TED imager, to optimize its performance for BNCT dosimetry. In this context, we require the use of pixelated detectors in order to cope with the very large count rates present in these treatments. We will discuss the characterization and implementation of a first pixelated crystal and its integration in the i-TED module and data process pipeline. Additionally, since BNCT requires imaging of large body regions, we have integrated LM-MLEM algorithms to enable 3D image reconstruction. For that purpose, we have developed in our lab a tomographic Compton-PET-capable rotatory system using i-TED modules.
References
[1] K. Hirose et al., “Boron neutron capture therapy using cyclotron-based epithermal neutron source and borofalan (10B) for recurrent or locally advanced head and neck cancer (JHN002): An open-label phase II trial”, Rad. & Onc. Vol 155, pp. 182-187, (2021)
[2] J. Balibrea-Correa et al., “Hybrid compton-PET imaging for ion-range verification: a preclinical study for proton, helium, and carbon therapy at HIT”, The Eur. Phys. Jour. Plus, Volume 140, 870 (2025)
[3] P. Torres-Sánchez et al., “The potential of the i-TED Compton camera array for real-time boron imaging and determination during treatments in Boron Neutron Capture Therapy”, App. Radiat. Isot. 217, 111649 (2025)
