Neutron autoradiography with nuclear tracks detectors: an imaging technique for Boron Neutron Capture Therapy

Abstract

Boron Neutron Capture Therapy (BNCT) is a radiation treatment modality for cancer based on the 10B(n,α)7Li (BNC) reaction. Knowledge of the spatial location of boron atoms is essential when considering a BNCT treatment, since the BNC reaction products cause lethal damage in a range comparable to cell diameter. Neutron autoradiography is a technique able to provide this information with high resolution at relatively low cost. First a boron-loaded biological matrix is laid on a nuclear track detector (NTD). By irradiating this assembly with thermal neutrons, the emitted particles of the BNC reaction produce damaged zones in the NTD along each incident ion trajectory, and by mapping these nuclear tracks boron spatial distribution in the sample can be assessed. In our laboratory, we have established different approaches: high fluence autoradiography (HFA), to observe boron microdistribution through differences in shades of gray; quantitative autoradiography (QTA), which allows the correlation between track density measurements and boron concentration; and UV-C sensitization of polymers (UVC-a), which produces an imprint of the biological material in the NTD, thus improving the spatial resolution. Moreover, we aim to develop a technique using commercial CMOS sensors in order to simultaneously detect the BNC events and the image of the biological sample during irradiation. The objective of this work is to describe the mentioned approaches and to discuss future perspectives.