Abstract
Purpose::
Periocular carboplatin has been shown to be useful as adjunctive therapy in the treatment of advanced retinoblastoma, especially in patients with vitreous seeding. Targeted local therapy may provide a means of augmenting systemic therapy while minimizing adverse effects. As sustained-release and other novel drug delivery vehicles are studied, a non-invasive means of visualizing the drug depot may prove useful in evaluating the efficacy of these techniques.
Methods::
Three patients with Reese-Ellsworth class 5B (International Classification E) retinoblastoma were studied. The age of the patients ranged from 14-30 months, and each of the patients had been previously treated with diode laser ablation and systemic chemoreduction with carboplatin, vincristine, and etoposide. During exam under anesthesia, B-scan ultrasonography was performed on these 3 patients immediately before and after sub-Tenon’s injection of carboplatin (2ml of 10mg/ml) and the depot of drug was demarcated and measured.
Results::
In each of the 3 cases, successful localization of carboplatin within sub-Tenon’s space was demonstrated. In one patient, moderate shadowing from tumor calcification partially obscured the visualization of the carboplatin. Marked improvement in vitreous seeding activity following a series of 3 injections was noted.
Conclusions::
Ultrasonography is an effective means of localizing periocular carboplatin. Each of the patients studied in this report demonstrated clear demarcation of a carboplatin depot following injection, despite moderate shadowing seen from calcification in one patient. Echography therefore may be a useful method of studying novel periocular drug delivery modalities.
Keywords: retinoblastoma • clinical (human) or epidemiologic studies: systems/equipment/techniques