Range verification in proton therapy: the LAPD demonstrator and its original approach to in-beam PET ballistic control

International audienceIn this presentation, original results obtained with the Large Area Pixelized Detector (LAPD) for in-beam ballistic control of hadrontherapy treatments are described. The LAPD system is a PET-like demonstrator built in order to test the feasibility of monitoring in real time, during irradiation, the ion range in the patient through the measurement of the beam-induced beta+ activity distribution. It has been designed with the aim of testing a few new and original solutions to overcome some of the in-beam PET challenges. These solutions are presented and their performances evaluated with data acquired with the 65 MeV proton beam of the Nice (France) protontherapy center are discussed. In particular, it is shown that the LAPD allows to monitor and detect in real time shifts of 1 mm in Bragg peak position in polymethyl methacrylate targets. Then, data to Monte Carlo simulation comparisons are presented and the performances on simulation of the activity profile reconstruction algorithm are described. The new high bandwidth LAPD data acquisition system will also be briefly discussed