Development of a Proton Computed Tomography system for pre-clinical tests

Proton Computed Tomography (pCT) is an imaging method under investigation with the aim to improve the accuracy of treatment planning and patient positioning in hadron therapy. A pCT system should be capable to measure tissue electron density with an accuracy better than 1% and with a spatial resolution better than 1mm. A first apparatus based on a silicon tracker and a YAG:Ce crystal calorimeter, with a 5×5 cm² active area, has been already developed by the authors in the framework of the PRIMA (Proton Imaging) collaboration and tested with proton beams with promising results. A second prototype with larger area (5×20 cm²) and improved data acquisition system is being designed. The details about this new prototype will be presented in this work.