Development of a pre-clinical compton probe prototype for prostate imaging

A prostate probe based on the Compton imaging principle could outperform imaging devices currently employed in prostate imaging. Electronic collimation overcomes the resolutionefficiency tradeoff imposed by mechanical collimators, and therefore Compton detectors may exhibit both high resolution and high counting efficiency under the appropriate conditions. Simulations predict better than 3 mm spatial resolution and about 10^¯3 efficiency for a system consisting of an endorectal prostate probe and scintillators above and below the patient. The development of a clinical prototype to validate the simulation results is underway. Thick pad silicon sensors (1 mm and 500 µm thickness) and associated readout electronics with energy resolution close to 1 keV FWHM have been developed. A preclinical prototype has been built employing these sensors as scatter detector. A resolution of 8 mm FWHM at 4.5 cm from the scatter detector was obtained with a 99mTc point-like source. Further improvements are foreseen with more optimized system and higher energy sources, for which a better resolution is expected.