Inclusion Criteria:  Patient treated at the Antoine LACASSAGNE Center for treatment by proton therapy Age ≥ 7 years old and ≤ 18 years old Patient, and parents for minor children, having read the information notice and signed the informed consent, Patient with social security coverage.  Exclusion Criteria:  Age < 7 years old and > 18 years old, Patient under general anesthesia, Patient suffering from wounds or infections in the head, deemed incompatible with the use of the helmet by the investigator, Patient suffering from respiratory problems, Patient suffering from a high level of claustrophobia, Patient followed for a psychiatric pathology, Patient suffering from unbalanced epilepsy, Patient suffering from visual (binocular vision) and / or hearing disorders preventing the use of virtual reality, Patient whose head circumference is insufficient for the use of the helmet, deemed incompatible with the use of the helmet by the investigator, Patient treated by radio chemotherapy.