- Possibility to trat by radiation withintensity modulated (fixed beams modulated or rotational modulation (TomoTherapy, dynamic arctherapy)) strictly respecting the constraints to organs at risk (Crystalline: 8 Gy max, Posterior chamber of the eye: 45 Gy max , optic nerve: 54 Gy max, chiasm: 54 Gy max, brain Stem: 2% 58 Gy D2 <64 Gy, Dmax <69 Gy spinal cord: 46 Gy max, healthy brain (brain - PTV): 60 Gy max 33%, 50 Gy to 50% and D100 <45 Gy to the brain in toto).