HAND-HELD OPTICAL COHERENCE TOMOGRAPHY MONITORING OF CHEMORESISTANT RETINOBLASTOMA.

ABSTRACT

PURPOSE: Retinoblastoma (Rb) is a potentially fatal intraocular malignancy in children, and hand-held optical coherence tomography (HH-OCT) can assist in submillimeter detection and monitoring after treatment of Rb. Retinoblastoma located in the macula, or those with chemoresistance, can be among the most difficult to manage. We describe HH-OCT features in a case of chemoresistant macular Rb that eventually responded to plaque radiotherapy after failing intravenous chemotherapy and intraarterial chemotherapy. METHODS: Observational case report. RESULTS: A 15-month-old girl with leukocoria was found to have Group D Rb in the right eye of 6-mm thickness and macular Group B Rb in the left eye of 4-mm thickness. She was treated with 6-monthly cycles of systemic intravenous chemotherapy and focal consolidation therapies to both eyes, with tumor regression in both eyes. However, macular tumor in the left eye demonstrated subsequent recurrence, from regressed thickness of 792 µm on HH-OCT to a dome-shaped hyperreflective retinal mass of >2000 µm thickness. Three cycles of intraarterial chemotherapy were sufficient for tumor regression down to 977 µm thickness on HH-OCT. Six months later, macular tumor in the left eye recurred again to >2000 µm thickness and necessitated plaque radiotherapy using apex dose of 35 Gy over 95.25 hours. Hand-held OCT confirmed rapid tumor regression to 722 µm after plaque treatment and regression remained stable at 6-month follow-up. CONCLUSION: Hand-held OCT was critical in assessment of Rb after failed intravenous chemotherapy and intraarterial chemotherapy and later documenting regression after plaque radiotherapy. Hand-held OCT is vital in providing cross-sectional imaging and measurements of small macular and paramacular Rbs.