Single-agent, minimal dose, minimal exposure intraarterial chemotherapy for retinoblastoma in a 4-month-old infant.

Purpose: To document minimal dose and minimal exposure of chemotherapy for unilateral retinoblastoma.

Methods: A 4-month-old infant developed leukocoria in the right eye and was found to have unilateral sporadic retinoblastoma.

Results: The right eye was classified as Group D retinoblastoma, with a single large tumor, moderate subretinal seeding, and total retinal detachment. The retinoblastoma measured 20 mm in basal dimension and 13 mm in ultrasonographic thickness. Options of enucleation, intravenous chemotherapy, and intraarterial chemotherapy were offered, but the latter was chosen because of anticipated, rapid, and more complete response with intraarterial rather than intravenous chemotherapy. After using low dose (3 mg) of single-agent melphalan delivered over 30 minutes into the ostium of the ophthalmic artery of the 4-month-old infant, a complete response with Type 1 regression (complete calcification) of the mass and resolution of all subretinal fluid was found. A second similar dose was delivered to ensure remission of all seeds and tumor with stable findings. Further chemotherapy was stopped. On 6 months of follow-up, the child displayed complete tumor control with 2 cycles of lowest dose (3 mg) intraarterial melphalan. There were no complications.

Conclusion: In infants younger than 6 months, low dose of only 3-mg single-agent melphalan could be sufficient to control retinoblastoma with minimal exposure.