  In this paper we prove that the choice of a suitable treatment of the
scintillator surfaces, along with suitable photodetectors electronics and
specific algorithms for raw data analysis, allow to achieve an optimal tradeoff
between energy, time and DOI resolution, thus strongly supporting the
feasibility of a prostate TOF- PET probe, MRI compatible, with the required
features and performance. In numbers this means a detector element of 1.5mm x
1.5mm x 10mm, achieving at the same time energy resolution around 11.5%,
time-of- flight resolution around 150 ps and DOI resolution even below 1 mm. We
stress that such a time resolution allows to increase significantly the Noise
Equivalent Counting Rate, and consequently improve the image quality and the
lesion detection capability. These individual values correspond to the best
obtained so far by other groups, but we got all of them simultaneously. In our
opinion this proof of principle paves the way to the feasibility of a TOF-PET
MRI compatible probe with unprecedented features and performance, not only
innovative for prostate radiotracer imaging but possibly also for other organs.
