Effectiveness of alternative routes of intra-arterial chemotherapy administration for retinoblastoma: Potential for response and complications

Objective: Intra-arterial chemotherapy (IAC) is now the first line treatment for selected patients with retinoblastoma (Rb). Typically, IAC is infused following the selective catheterization of the ophthalmic artery (OA) on the affected side. However, in some patients, the OA alone may not provide vascular supply to the tumor, whereas in other instances the efficacy of IAC could be compromised due to the presence of prominent collateral vessels from the external carotid artery (ECA). We report our experience with catheterizing vessels other than the OA for IAC treatment for Rb. Methods: After institutional review board approval, a retrospective analysis was conducted of electronic medical records and imaging of our Rb population. Results: We identified 13 patients who received IAC for Rb treatment. Of these, five patients required alternative methods of chemotherapy delivery other than through the OA, totaling 17 treatments. Two patients needed balloon-assisted occlusion of the ECA, two patients required selective catheterization of the middle meningeal artery, and one patient had no internal carotid artery supply to the choroidal blush, thus the superficial temporal artery provided access for IAC. Total globe salvage rate was 76% and 80% with the alternative route subset. Conclusions: Alternatives to the OA may be necessary to deliver IAC for selected cases of Rb. These routes can be safe and effective. However, thorough understanding of the orbital blood supply is essential. Whether these alternative IAC methods result in similar outcomes to OA infusions has not been established.