High-Dose Intravitreal Topotecan for Recurrent Retinoblastoma, Subretinal Seeds, and Vitreous Seeds in 13 Consecutive Cases

Purpose: To evaluate the efficacy and safety of high-dose intravitreal topotecan (IvitTopo) for recurrent retinoblastoma. Methods: There were 13 patients with recurrent retinoblastoma treated with high-dose IvitTopo (90 micrograms (μg)/0.18cc-100 μg/0.20cc). The primary outcome measures were tumor control, globe salvage, and treatment complications. Results: At date first seen (DFS), median patient age was 9 months, and the affected eye was classified as International Classification of Retinoblastoma (ICRB) Group B (n=2, 15%), Group C (n=3, 23%), or Group D (n=8, 62%) retinoblastoma with initial therapy of intravenous chemotherapy (n=9, 69%) or intra-arterial chemotherapy (n=4, 31%). Recurrent tumor was detected at median 10 months as solid tumor (n=3), subretinal seeds (n=10), and/or vitreous seeds (n=3) and high-dose IvitTopo (median 3 injections) delivered at monthly intervals. Additional chemotherapy was delivered by intra-arterial (n=8, 62%) or intravenous (n=1, 8%) routes, and 1 eye received additional cryotherapy (n=1, 8%). In 3 cases (23%) there was no additional therapy. At mean follow-up of 9 months, regression of solid tumor, subretinal seeds and vitreous seeds was achieved in 12 cases (92%), and globe salvage was achieved in all cases (n=13, 100%). Of those 3 eyes treated with high-dose IvitTopo alone, tumor control was initially achieved in all cases (100%), but one case that previously demonstrated massive vitreous seeding showed late recurrence of a solitary vitreous seed at 8 months. There were no complications. Conclusions: High-dose IvitTopo is an effective and safe therapy for recurrent retinoblastoma, in conjunction with other therapy, and possibly as a stand-alone therapy.