In proton therapy, how to treat a first patient with a prototype?

After several years of common development the accelerator building companies IBA (Louvain-la-Neuve, Belgium) and AIMA (Nice, France) built a prototype synchro-cyclotron (S2C2) and in 2016, the Centre Antoine LACASSAGNE (Nice, France) treated the first patient with the first ProteusONE (IBA) protontherapy machine, including the S2C2 and a compact gantry beam line. Treating patients with a prototype includes a lot of challenges and uncertainties about the issue. This talk is about this journey and the experiments achieved with this new prototype: absolute dose measurements, range determination with ionoacoustics etc. The Centre Antoine LACASSAGNE is one of the two proton therapy centers in France and this talk gives also an overview of the proton therapy strategy in France nowadays.