Intravitreal melphalan for refractory or recurrent vitreous seeding from retinoblastoma.

OBJECTIVE To evaluate the efficacy and complications of intravitreal chemotherapy for viable vitreous seeding from retinoblastoma. METHODS Intravitreal injection of melphalan (8-50 μg in 0.05 mL) followed by injection site cryotherapy. RESULTS Among 12 treated cases, success with control of vitreous seeds was achieved in 10 of 12 cases at immediate follow-up (0-3 months), 8 of 10 cases at short-term follow-up (3-6 months), and 6 of 10 cases at long-term (>6 months) follow-up. Among those 8 cases that received an 8- to 10-μg dose, control was achieved in 6 of 8 cases at immediate follow-up, 5 of 7 cases at short-term follow-up, and 3 of 7 cases at long-term follow-up. Complications with the 8- to 10-μg dose were minor and included preretinal hemorrhage and retinal vasculitis with retinal pigment epithelial alterations. Of those 4 that received a 50-μg dose, immediate, short-term, and long-term control was 100%, but complications of cataract, vitreous hemorrhage, subretinal hemorrhage, severe hypotonia, and phthisis lead to enucleation in 2 cases. There was no case of orbital tumor recurrence or retinoblastoma metastasis (follow-up range, 8-66 months). CONCLUSIONS Intravitreal melphalan for recurrent vitreous seeds from retinoblastoma appears to provide vitreous seed control in some patients. A high dose (50 μg) of melphalan is toxic and should be avoided.