Results from a first prototype of a Compton prostate probe

A first prototype of a Compton prostate probe has been built using a stack of five 4times1 cm², 1 mm thick silicon pad detectors as a scatter detector, surrounded by three scintillation detectors in which the absorption of the scattered photons takes place. The silicon pad dimensions are 1.4times1.4 mm which provide the required spatial resolution. The energy resolution in the silicon sensors is about 1.4 keV FWHM as determined from several gamma sources. The results obtained validate the simulation predictions that foresee an improvement over current SPECT techniques by a factor 16-40 in sensitivity and 4-5 in spatial resolution simultaneously for an intra-rectal probe built employing this concept and placed at 2 cm from the prostate