Compton imaging for dosimetry and real time monitoring in boron neutron capture therapy

Boron Neutron Capture Therapy (BNCT) is an emerging radiotherapy technique that exploits the high neutron capture cross-section of 10 B to deliver targeted high-LET radiation to tumor cells while sparing surrounding healthy tissue. Effective clinical implementation requires accurate in vivo determination of boron concentration during treatment to enable precise dose monitoring. The i-TED Compton Camera Array, originally developed for high count-rate neutron-induced reaction measurements at CERN, offers promising capabilities for BNCT dose monitoring due to its low neutron sensitivity, high efficiency, and large field-of-view. We report on a series of experiments at the FIPPS beamline (ILL, France) to evaluate i-TED performance under progressively challenging background and count rate conditions, including borated water and hydrogen-rich environments mimicking clinical scenarios. Results show that while the system can identify the 478 keV gamma-rays from boron under realistic boron-to-hydrogen ratios, high count rates induce gain shifts that degrade low-energy gamma detection. Strategies to mitigate these effects, including optimized scintillator thicknesses and angular event selection, are proposed. These findings provide a clear path toward adapting i-TED for real-time BNCT dose monitoring in clinical environments.