Episcleral plaque brachytherapy for retinoblastoma.

Abstract

The purpose of this study was to report our experience using episcleral plaque brachytherapy (EPBRT) to treat retinoblastoma and to demonstrate its applicability in multimodality treatment. We treated 26 tumors in 25 eyes from a group of 21 children with unilateral (n = 4) or bilateral (n = 17) retinoblastoma. The group comprised 8 girls and 13 boys; the median age was 25 months (range: 2-64 months) at the time of EPBRT. Iodine-125 ((125)I) was used for all applications. The median dose was 44 Gy (range: 35-47.6 Gy). EPBRT was administered primarily at the time of relapse after primary chemotherapy or radiation therapy. For eyes treated with EPBRT, the eye preservation rate was 15/25 with a median follow-up of 47 months (range: 2-198 months); the lesion control rate was 25/26 with a median follow-up of 13 months (range: 1-140 months). The median time to additional whole-eye treatment after EPBRT was 12 months (range: 2-105 months). Similar to previously reported series, EPBRT shows a high rate of successful tumor control as a primary treatment for retinoblastoma, as well as a secondary therapy at the time of relapse. EPBRT also allows for a clinically significant delay in the time to additional measures for the affected eye. Therefore, EPBRT should be considered as a form of local ophthalmic therapy that avoids or delays the use of external-beam radiotherapy, especially for patients primarily treated with chemotherapy who might require consolidation therapy.