Preoperative MRA for Patients with Retinoblastoma Undergoing Intra-Arterial Chemotherapy.

BACKGROUND AND PURPOSE: Intra-arterial chemotherapy (IAC) is a potent treatment for patients with pediatric retinoblastoma (RB). Ophthalmic artery (OA) navigation via the ICA can be technically challenging; and in cases with robust anastomoses to the OA from the middle meningeal artery (MMA), the latter may serve as an alternative route. Our study evaluates the ability of preprocedural MRA to identify OA variants and the presence of MMA-to-OA/lacrimal artery (LA) anastomoses to enhance successful delivery of IAC in this population. MATERIALS AND METHODS: Consecutive patients with RB admitted for IAC treatment at a tertiary pediatric hospital were identified from October 2018 to January 2025. The morphology of the OA origin and the presence of MMA-OA anastomoses were assessed on preprocedural MRA and confirmed on DSA. RESULTS: A total of 13 patients who underwent 42 procedures were included, with a median age of 11 months (interquartile range, 11-21 months). The OA origin was visualized on MRA in 12 (92%) cases. MMA-OA/LA anastomoses were seen on MRA for 6 (46%) patients, all confirmed on DSA. Among patients with no MRA evidence of anastomoses, none were found to have anastomoses on DSA. MMA-OA anastomoses were used as the primary delivery route of IAC for 3 patients (50% of patients with a confirmed presence of MMA-OA anastomoses). Overall procedural success was 98% (41/42). CONCLUSIONS: Preoperative MRA is an accurate tool for identifying OA origin variants and MMA-OA anastomoses, which may assist in optimizing IAC delivery for patients with pediatric RB, while minimizing radiation.