Preliminary characterization of a CdZnTe photon detector for BNCT-SPECT

Abstract The effectiveness of Boron Neutron Capture Therapy (BNCT) treatment depends on the amount of radiation dose deposited locally by the reaction  10 B ( n , α ) 7 Li in the tumour; however, the local and real time measurement of this quantity during the neutron irradiation is a big challenge. To evaluate the dose it is necessary to know the spatial distribution of the  10 B concentration and thermal neutron flux in the tissue during the irradiation. One technique to solve this problem relies on the on-line detection of the 478 keV  7 Li de-excitation photons that can be used to map the spatial distribution of the reaction rate of the  10 B ( n , α ) 7 Li. The present work has been developed within a project aiming to develop a Single Photon Emission Computed Tomography (SPECT) system based on CdZnTe (CZT) semiconductor detector. This work studied the performances of a 5 × 5 × 20 mm 3 CZT prototype detector focusing on the energy resolution and detection efficiency inside the energy range 200–1400 keV. The energy resolution at 478 keV is ∼ 3% and the detection efficiency is around 6%. These preliminary results confirms the feasibility of a CZT detector as a sensitive unit for a BNCT-SPECT imaging system.