Changes in the MRI Signal in Patients With Benign Tumors of the Brain and Meninges Treated With Proton Therapy: Impact of TEL and the Biological Dose Received

"1.5 Tesla MRIs, usually used as pre-treatment and, between 3 and 6 months after irradiation, are replaced in the study by 3 Tesla MRIs (pre-treatment and at 6 months)~In addition, two additional MRIs, also performed with a 3 Tesla magnetic field, will be performed:~* During treatment when half of the prescribed dose has been delivered.~* 1 month after the end of the irradiation."