Prevalence of optic pathway glioma in NF1: a systematic review and meta-analysis focused on MRI surveillance

Optic pathway gliomas (OPGs) are among the most frequent central nervous system tumors in children with neurofibromatosis type 1 (NF1), yet their prevalence has not been systematically synthesized. Pooled prevalence estimates are important to inform clinical surveillance practices, particularly given the critical role of early symptom detection in preserving vision and the debate regarding magnetic resonance imaging (MRI) surveillance in asymptomatic patients. The purpose of this study was to investigate the prevalence of OPG in children (<18 years) with NF1 based on pooled data in the literature and describe its variability.

The databases of PubMed, Embase, Scopus, Web of Science, and Cochrane CENTRAL were searched without language or date restrictions. Eligible studies reported OPG prevalence in patients with NF1 <18 years of age. Two reviewers independently screened studies, extracted data, and assessed quality. Studies meeting minimum methodological quality were included in our meta-analysis, and subgroup and meta-regression analyses were performed.

A total of 38 studies encompassing 6,314 patients were included in the qualitative synthesis; 27 studies (5,485 patients) were subject to meta-analysis. The pooled prevalence of optic pathway gliomas was 17% (95% CI, 14%-20%), with low certainty according to GRADE. Subgroup analysis found no significant association in reported rates across MRI surveillance strategies, and a focused meta-regression directly comparing routine and symptom-based approaches showed similar results. Analyses by continent, sample size, and quality score revealed no significant differences.

Our results provide the first pooled evidence prevalence estimate of OPG in children and adolescents with NF1 and highlight the importance of close monitoring, reinforcing guidelines that favor a symptom-based MRI approach and suggesting no clear advantage of routine imaging.