Baseline and Post-NACT Imaging in Retinoblastoma With Optic Nerve Involvement: Can MRI Predict Prognosis?

Purpose: To describe a staging system for optic nerve invasion using magnetic resonance imaging (MRI) and report any correlation with survival outcome.

Methods: This was a ambispective study. Twenty-one patients with retinoblastoma who had optic nerve involvement on MRI were staged at baseline based on contrast enhancement and/or thickening and length of involvement. Response to neoadjuvant chemotherapy (NACT) was noted according to proposed response evaluation criteria and results were correlated with survival outcome.

Results: Baseline MRI staging was able to predict event-free survival (EFS) ( = .0015) using the log-rank test for trends. Patients with optic nerve enhancement alone showed 100% survival prognosis. Optic nerve thickening cases with complete or partial response to NACT showed better EFS ( > .90) than those with stable disease according to response evaluation criteria.

Conclusions: The modified staging system for optic nerve invasion used in the current study significantly predicted EFS. The study also showed that response to NACT may be affected by baseline staging. The authors recommend that cases with optic nerve enhancement only, irrespective of the length of involvement (stage 0), may be treated with upfront enucleation. Cases with optic nerve thickening may be staged to evaluate the correlation with survival outcome in a larger cohort in future studies. .