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INTRAVITREOUS CHEMOTHERAPY FOR ACTIVE VITREOUS SEEDING FROM RETINOBLASTOMA: Outcomes After 192 Consecutive
Carol L Shields1, Alexzandra M Douglass, Meriem Beggache
1Ocular Oncology Service, Wills Eye Hospital, Thomas Jefferson University, Philadelphia, Pennsylvania.
Purpose:
To investigate on the safety and efficacy of intravitreous chemotherapy for retinoblastoma seeding in a relatively large cohort and provide information on the necessary number of injections and long-term control.
Methods:
Retrospective interventional case series of 40 consecutive eyes with viable vitreous seeding after standard treatment of retinoblastoma. All eyes received intravitreal melphalan injection (20-30 μg) and additional topotecan (20 μg) as needed using the trans pars plana route with triple freeze-thaw cryotherapy at needle withdrawal for prevention of extraocular seeding for planned six cycles.
Results:
The mean patient age at presentation was 36 months, and interval to need for vitreous injection was 14 months. Viable vitreous (n = 40 eyes) and additional subretinal (n = 2 eyes) seeds were documented. There was a total of 192 injections using melphalan (n = 148) and/or topotecan (n = 44) with mean number of injections per eye of melphalan at 4 (median, 4; range, 1-6) and topotecan at 3 (median, 3; range, 1-5). Fewer than six planned melphalan injections (n = 31 cases, 78%) were necessary because of rapid and complete vitreous seed control (n = 30 eyes) or melphalan allergy (n = 1 eye). Fewer than six planned topotecan injections (n = 14 cases, 100%) were necessary because of rapid and complete vitreous seed control in all cases. At median 3-year follow-up, therapeutic success with continued seed regression was observed in all 40 eyes (100%). Globe salvage was attained in 35 cases (88%), and enucleation (n = 5) was necessary for extensive recurrent subretinal seeds (n = 2), neovascular glaucoma with vitreous hemorrhage (n = 2), and hemorrhagic retinal necrosis (n = 1). Side effects included focal retinal pigment epithelial mottling at the site of injection (n = 12), minor focal paraxial lens opacity (not requiring cataract surgery) (n = 11), transient focal vitreous hemorrhage (n = 5), transient hypotony (n = 3), transient retinal hemorrhage (n = 2), optic disc edema (n = 1), and hemorrhagic retinal necrosis (n = 1). There was no case of endophthalmitis, extraocular tumor extension, metastasis, or death.
Conclusion:
Intravitreal melphalan and/or topotecan injection for retinoblastoma vitreous seeding provides lasting tumor control at 3 years with approximately 4 injections.
