Retinoblastoma frontiers with intravenous, intra-arterial, periocular, and intravitreal chemotherapy

Abstract

In this report, we explore retinoblastoma diagnostic accuracy and review chemotherapy alternatives for retinoblastoma using intravenous, intra-arterial, periocular, and intravitreal routes. A review of 2775 patients referred for management of retinoblastoma, disclosed 78% with confirmed retinoblastoma and 22% with simulating lesions, termed pseudoretinoblastomas. Children ≤2 years old showed leading pseudoretinoblastomas of persistent fetal vasculature, Coats disease, and vitreous haemorrhage, whereas those >5 years showed simulators of Coats, toxocariasis, and familial exudative vitreoretinopathy. The diagnosis of retinoblastoma should be established before planning therapeutic strategy. Chemotherapy strategy depends on tumour laterality and stage of disease. If bilateral retinoblastoma, intravenous chemotherapy (IVC) is important as first-line therapy for control of intraocular disease, prevention of metastasis, and reduction in prevalence of pinealoblastoma and long-term second malignant neoplasms. Bilateral groups D and E retinoblastoma receive additional subtenon's carboplatin boost for improved local control. If unilateral disease is present, then intra-arterial chemotherapy (IAC) is often considered. IAC can be salvage therapy following chemoreduction failure. Unilateral retinoblastoma of groups D and E are managed with enucleation or globe-conserving IVC and/or IAC. Intravitreal chemotherapy is cautiously reserved for recurrent vitreous seeds following other therapies. In conclusion, the strategy for retinoblastoma management with chemotherapy depends on tumour laterality and stage of disease. Bilateral retinoblastoma is most often managed with IVC and unilateral retinoblastoma with IAC, but if advanced stage, combination IVC plus IAC or enucleation.

Figure 1

IVC (chemoreduction) for retinoblastoma. (a, b) Before IVC showing viable retinoblastoma in the right (a) and left (b) eyes. (c, d) After IVC showing complete tumour regression in the right (c) and left (d) eyes.

Figure 2

IAC for retinoblastoma. (a, b) Primary IAC showing before (a) and after (b) three cycles of melphalan. (c, d) Secondary IAC following IVC but with recurrence of macular and inferior tumours (c) that responded completely (d) to three cycles of melphalan.

Figure 3

Combination primary IVC plus secondary IAC for bilateral group D retinoblastoma. (a, b) Active retinoblastoma at first visit (a) that responded to primary IVC with tumour regression (b). (c, d) Recurrent subretinal seeds (c) necessitated further treatment with IAC (d) with ultimate seed control.