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 largest 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.