Predictors in Optic Pathway Gliomas in Neurofibromatosis Type 1: A Single Center Study

Background/Aim: Among NF1-dependent tumors, the most common are optic pathway gliomas (OPGs). The objective of this study was the retrospective analysis of the course, indications for treatment, and effects of therapy for NF1-OPGs. Patients and Methods: We analyzed demographics, clinical and genetic data, imaging and ophthalmological parameters, their impact on therapeutic decisions, and the effectiveness of the therapy in 92 patients. Results: OPGs were unilateral in 55.4% of patients and bilateral in 44.6%. Post-contrast enhancement in MRI was observed in 67.4%. Oncological treatment was required in 16.3% of patients with median age 3.8 years. Factors significant in multivariate analysis contributing to the need of oncological treatment were: amblyopia and proptosis. Factors contributing to amblyopia were: strabismus, proptosis, co-occurrence of epilepsy, bilateral OPGs, and thickness of the optic nerve ≥ 8 mm. The first line of oncological treatment included vincristine + carboplatin or monotherapy with vinblastine. The use of subsequent lines of oncological treatment was necessary in 46.7% patients. Conclusions: The following conclusions, suggest modification of the approach in the management of patients with NF1-OPG, summarize the presented study: (1) perform the first MRI after the age of 1 year, (2) reduce the frequency of follow-up scans in the first year of observation in patients with isolated involvement of intraocular and/or intraorbital segments of the optic nerve, (3) refrain from administering contrast during control MRI examinations of the orbits after OPG diagnosis; (4) in patients with co-occurring psychomotor delay or treated with antiepileptic drugs, do not make decisions about oncological therapy when visual acuity deterioration is observed, without progression in optical coherence tomography (OCT), visual evoked potentials (VEP), and MRI.