Treatment is done without hospitalization. Treatment with a beam of protons is painless, therefore anesthesia is not required. However, children tend to undergo proton therapy under anesthesia in order to achieve complete immobility of the small patient. Before the beginning of each procedure the patient is laid on the couch and fixed with an individually manufactured device. To make sure that the patient is positioned correctly, several x-rays are taken before each session. After that, the medical staff goes to the next room, where specialists monitor the process of treatment on the computer screen. During all the time of treatment, the staff is able to monitor the patient's position and, if necessary, adjust it. The duration of each session depends on the type of tumor and the stage of the pathological process. The proton beam irradiation itself lasts only 1-3 minutes, whereas the total length of stay in the treatment room, together with the preparation for the procedure, takes about 20-30 minutes.