This study from the Heidelberg group reported outcomes of 32 patients with primary optic nerve sheath meningiomas (ONSMs) treated by proton radiation. With a median follow-up time of 39.5 months, the 5-year local progression-free survival was estimated at 100%, with 84.4% of patients reporting improvement or stability in visual acuity during their last follow-up. Radiation-induced optic neuropathy was encountered in 9.4%. The authors conclude that this data demonstrates proton beam therapy as a safe and effective treatment alternative in the therapeutic management of ONSMs.