Treatment of isolated pediatric optic nerve glioma: A nationwide retrospective cohort study and systematic literature review on visual and radiological outcome

Abstract

Background: Progressive isolated optic nerve glioma (ONG) in children is a rare disease, treated with various modalities. A global treatment consensus is not available.

Methods: We conducted a national retrospective multicenter cohort study (1995-2020) to investigate how different treatment strategies impact outcome for ONG in children, by assessing treatment responses to systemic anticancer therapy (SAT), surgery, and radiotherapy for ONG. The primary endpoints included changes in best-corrected visual acuity (BCVA) and tumor volume (TV) on MRI, both evaluated at the start and end of therapy and at long-term follow up.

Results: A total of 21 ONGs (20 patients) received SAT (n = 14 (66.7%)), surgery (n = 4 (19.0%)), and radiotherapy (n = 3 (14.3%)). After SAT BCVA stabilized or improved in 66.6% (n = 4) and the TV decreased by a median of 45.1% (range: -88.6% to +31.5%) (n = 13). Before resection two eyes were already blind. After resection BCVA decreased to blindness in one eye. In total all four eyes were blind after resection. After first-line RT BCVA decreased in 66.7% of ONG to counting fingers or less, TV increased <3 months after RT by a median of 47.3% (range: -42.8% to +245.1%) (n = 3), followed by a long-term decrease of 94.4 and 13.8% (n = 2), respectively.

Conclusion: SAT appears to be the preferred modality for progressive ONG in case of potential rescue of visual functions. Complete resection of ONG appears effective to reduce proptosis in case of preexisting blindness. The use of radiotherapy requires careful consideration due to the risk of severe visual impairment and secondary disease.

Keywords: MRI; children; low grade glioma; optic nerve glioma; response assessment; visual function.