Purpose: To evaluate the efficacy of multiagent chemotherapy in the neoadjuvant treatment of retinoblastoma.
Design: Noncomparative, prospective case series.
Participants: Twenty consecutive patients with multifocal intraocular retinoblastoma (4 unilateral, 16 bilateral [36 eyes]).
Intervention: Eight cycles of chemotherapy with carboplatin and vincristine were administered at 3-week intervals over a 6-month period. Supplemental therapy was withheld until disease progression was documented.
Main outcome measures: Disease progression (defined as tumor growth, vitreous or subretinal seed progression, and new tumor formation), delay of external beam radiotherapy, and ocular survival.
Results: Thirty-six eyes were treated. Eighteen eyes had Reese-Ellsworth group I-III tumors, and 16 eyes had Reese-Ellsworth group IV-V tumors at diagnosis. Two patients, who had unilateral disease at diagnosis, subsequently had tumors develop in the contralateral eye. Nineteen of 20 patients (95%) completed eight cycles of chemotherapy without disease progression. Three eyes of three different patients were successfully treated with chemotherapy alone. Thirty-three of 36 eyes (92%) progressed after completion of chemotherapy: 15 of the 18 eyes (83.3%) with Reese-Ellsworth group I-III and 16 of 16 eyes (100%) with Reese-Ellsworth group IV-V tumors. Seventeen eyes (52%) had growth of a tumor, whereas 14 eyes (42%) had progressive vitreous seeding, and 2 eyes (6%) had new tumors develop. Fifteen eyes (42%) required external beam radiotherapy. Twenty-nine of 36 (80.5%) eyes were salvaged. The median follow-up after chemotherapy was 19 months (range, 3-42 months).
Conclusions: Multiagent chemotherapy alone does not ensure a cure for multifocal intraocular retinoblastoma. Supplemental focal therapy is needed to control disease progression.