Retinoblastoma Control With Primary Intra-arterial Chemotherapy: Outcomes Before and During the Intravitreal Chemotherapy Era

Purpose: To compare outcomes of intra-arterial chemotherapy for retinoblastoma as primary therapy before (Era I) and during (Era II) the intravitreal chemotherapy era. Methods: In this retrospective interventional case series at a tertiary referral center, 66 eyes of 66 patients with untreated unilateral retinoblastoma were used. intra-arterial chemotherapy into the ophthalmic artery under fluoroscopic guidance was performed using melphalan in every case, with additional topotecan as necessary. Intravitreal chemotherapy using melphalan and/or topotecan was employed as needed for active vitreous seeding. Globe salvage was measured based on the International Classification of Retinoblastoma (ICRB) during two eras. Results: The two eras encompassed 2008 to 2012 (intra-arterial chemotherapy alone, Era I) and 2012 to 2015 (intra-arterial chemotherapy plus intravitreal chemotherapy, Era II). Over this period, there were 66 patients with unilateral untreated retinoblastoma treated with primary intra-arterial chemotherapy. A comparison of features (Era I vs Era II) revealed no significant difference in mean patient age (24 vs 24 months), ICRB groups, mean larg-est tumor diameter (19 vs 17 mm), mean largest tumor thickness (10 vs 10 mm), vitreous seed presence (56% vs 59%), subretinal seed presence (67% vs 62%), retinal detachment (70% vs 66%), or vitreous hemorrhage (0% vs 5%). There was no significant difference in mean number of intra-arterial chemotherapy cycles (3 vs 3.1) or intra-arterial chemotherapy dosages. Following therapy, there was a significant difference (Era I vs Era II) in the need for enucleation overall (44% vs 15%, P =.012), especially for group E eyes (75% vs 27%, P =.039). Four of the eyes that initiated therapy in Era I later required intravitreal chemotherapy during Era II. The enucleation rate was 0% for groups B and C in both eras and non-significant for group D (23% vs 13%). There were no patients with stroke, seizure, limb ischemia, extraocular tumor extension, secondary leukemia, metastasis, or death. Conclusions: The current era of retinoblastoma management using intra-arterial chemotherapy plus additional intravitreal chemotherapy (as needed for vitreous seeding) has improved globe salvage in eyes with advanced retinoblastoma.