Intravitreal Chemotherapy for Vitreous Seeding Caused by Retinoblastoma

Vitreous seeding is one of the primary reasons for treatment failure following conservative management of retinoblastoma.1,2 In our hands, until early 2006, most children with recurrent vitreous seeding were managed with plaque radiotherapy, external beam radiotherapy, or enucleation.1,2 In 2006, following the initial experience of Kaneko and Suzuki in Japan,3 we performed the first intravitreal injection of melphalan for the management of retinoblastoma vitreous seeds in the United States.4 Quite cautiously, we sequentially injected the affected eyes of three patients with previously treated retinoblastoma and extensive recurrent vitreous seeding. Our initial experience was that all three cases showed dramatic response with rapid seed regression. However, due to the low chemotherapy dose (8 μg/0.1 cc melphalan) used at that time, seed recurrence was a problem. Since then, melphalan dose escalation to between 20 μg/0.1 cc and 30 μg/0.1 cc has allowed reliably improved results, with vitreous seed control in nearly every case.5,6 Today, vitreous seeds no longer readily necessitate enucleation, as these cases can be managed safely and reliably with intravitreal chemotherapy (IVitC).4-6 In 2012, Ghassemi and Shields4 and Munier et al7 each reported on the safety and efficacy of IVitC for vitreous seeds. Munier et al noted that IVitC was no longer prohibited for retinoblastoma management.7 This approach has now been adopted at almost all major retinoblastoma centers worldwide. In this article we describe a child with retinoblastoma treated initially with intraarterial chemotherapy (IAC) and then subsequently with intravitreal melphalan for recurrent vitreous seeding. CASE REPORT A 26-month-old male initially presented for evaluation of a lazy eye with leukocoria and was found to have retinoblastoma. The patient was referred to Wills Eye Hospital Ocular Oncology Service for an opinion. On examination, visual acuity was fix and follow in the right eye (OD), and no fix or follow in the left eye (OS). Intraocular pressures were normal in both eyes. OD was healthy, but OS showed obvious leukocoria (Figure 1). On funduscopy, there was total retinal detachment up against the back of the lens, with exophytic retinoblastoma classified as group D and measuring 16.0 mm in basal dimension and 10.6 mm in thickness (Figure 2A). Both vitreous and subretinal seeds were noted. Ultrasonography and magnetic resonance imaging using T1and T2-weighted scans showed