Fractionated stereotactic radiotherapy for optic nerve gliomas

Optic nerve gliomas represent approximately 5% of all pediatric intracranial tumors. Due to the highly variable clinical course optimal treatment is still discussed controversial. Since they often have little or no growth potential there is a strong recommendation for wait-and-see strategies. In patients with progressive loss of vision or local tumor progression in MR imaging, fractionated radiotherapy provides the greatest possibility of vision preservation. Radiotherapy plays an important role in these challenging tumors achieving high long-term local control rates and improved or stable visual function in approximately 90% of the cases. Recommended dose prescriptions vary between 45 and 54 Gy in standard fractionation. However, in children less than 5 years of age the role of radiotherapy is unclear. Here, chemotherapy is often used to delay radiotherapy treatment to avoid neuropsychological morbidity after irradiation during neurodevelopment. Typical late complications of radiotherapy include endocrinopathy,  vasculopathy, cognitive deficits and cataracts, especially in younger patients. Modern high-precision radiotherapy techniques like fractionated stereotactic radiotherapy (FSRT) are capable to achieve high local control rates with reduced treatment related late morbidity. Prospective randomised trials are needed to further define the role of modern radiotherapy techniques, especially in younger patients in a multimodal treatment approach.