Primary optic nerve sheath meningioma - Stereotactic fractionated radiation therapy as an emerging treatment of choice

BACKGROUND. Radiotherapy (RT) has occasionally been practiced in the treatment of optic nerve sheath meningioma (ONSM). Recently, stereotactic fractionated RT (SFRT) has been introduced as a tool with better precision for RT delivery. A comprehensive review was undertaken to provide more insight into this matter. METHODS. A literature search was performed to identify reports dealing with both clinical aspects (diagnosis) and treatment in ONSM, focusing on RT in primary (p)ONSM. In particular, major emphasis was placed on the role of SFRT in pONSM. RESULTS. SFRT was capable of achieving excellent local tumor control, with improved/stable functional capacity in >= 80%, accompanied with very low toxicity in meticulously planned RT. This holds true for the majority of patients with progressive functional loss and probably the vast majority of those with some degree of functional loss at presentation. Those blind at presentation benefit from postoperative RT, whereas those with only minimal functional loss at presentation must be carefully selected for the best treatment, because a wait-and-see policy will inevitably lead to serious dysfunction or even blindness. CONCLUSIONS. SFRT should be considered the treatment of choice for the majority of patients with pONSM. Every effort should be made to further investigate the remaining questions in this disease, such as optimal timing for the patients with no or slight vision loss at presentation.