Thanks to the intrinsic qualities of the proton beam, proton therapy will reduce adverse effects of irradiation. The Proteus®One is the latest generation of proton therapy equipment, enabling the Centre Antoine Lacassagne to expand its range of treatments by carrying out new proton therapy treatments. It has an innovative compact isocentric rotating head (Gantry) that allows the radiation beam to be directed at different angles around the patient. In some cases, two beams are used to treat tumours, and by convention, both beams are delivered during the same session. However, it is necessary to position the patient before each beam, which is time-consuming because 2 beams have to be positioned very precisely each day. The aim of this study is therefore to assess the toxicity of proton therapy delivered by a single daily beam compared with proton therapy delivered by two daily beams, which is the conventional technique.