  Treatment planning systems at proton-therapy centres generally use X-ray
computed tomography (CT) as primary imaging technique to infer the proton
treatment doses to tumour and healthy tissues. However, proton stopping powers
in the body, as derived from X-ray images, suffer from important proton-range
uncertainties. In order to reduce this uncertainty in range, one could use
proton-CT images instead. The main goal of this work is to test the
capabilities of a newly-developed proton-CT scanner, based on the use of a set
of tracking detectors and a high energy resolution scintillator for the
residual energy of the protons. Different custom-made phantoms were positioned
at the field of view of the scanner and were irradiated with protons at the CCB
proton-therapy center in Krakow. We measured with the phantoms at different
angles and produced sinograms that were used to obtain reconstructed images by
Filtered Back-Projection (FBP). The obtained images were used to determine the
capabilities of our scanner in terms of spatial resolution and proton Relative
Stopping Power mapping and validate its use as proton-CT scanner. The results
show that the scanner can produce medium-high quality images, with spatial
resolution better than 2 mm in radiography, below 3 mm in tomography and
resolving power in the RSP comparable to other state of the art pCT cameras.
