Addition of Intravitreal Carboplatin with Melphalan for Management of Vitreous Seeding in Retinoblastoma

Purpose: To evaluate the efficacy and toxicity of intravitreal carboplatin plus melphalan for the treatment of vitreous seeds in eyes with retinoblastoma (RB).

Methods: This retrospective series at a tertiary referral center included 22 consecutive RB patients who had received intravitreal carboplatin (16 μg per 0.05 ml) combined with melphalan (30 μg in 0.03 ml) [IVi (Ca-Me)] for treatment of vitreous seeds. Tumor control and drug toxicities were recorded.

Results: There were 22 eyes of 22 patients, divided into primary group (n = 13) without history of previous intravitreal chemotherapy (IViC) and refractory group (n = 9) with history of previous IViC using melphalan and/or topotecan. The demographics and clinical findings of the primary and refractory groups did not differ significantly. The 6-month follow-up revealed complete vitreous seed control (77% vs. 89%, p = 0.47). Vitreous seed recurrence was detected in 1 eye of each group at 6 months. During the next 18-month follow-up period, no recurrence of seed was observed. The response to IVi (Ca-Me) was not significantly influenced by previous IViC (p = 0.70), primary systemic or intra-arterial chemotherapy (p = 0.45), or the type of regression (p = 0.35). The most common tumor treatment complications were retinal detachment (RD) (n = 2), early hypotony (n = 2) and late hypotony (n = 4, unrelated), cataract (n = 2), and severe pigment dispersion (n = 1). Enucleation was performed in 8 eyes, for total RD (n = 1), phthisis bulbi (n = 5), and extensive solid tumor recurrence (n = 2). There was no case of orbital invasion, systemic metastasis, or death.

Conclusion: Based on this interventional case series for primary and refractory vitreous RB seeds, carboplatin plus melphalan therapy may be effective with few toxic side effects.