COMBINED CHEMOREDUCTION AND ADJUVANT TREATMENT FOR INTRAOCULAR RETINOBLASTOMA

Objective: The purpose of the study is to investigate chemoreduction a nd adjuvant treatment (AT) for retinoblastoma and its effect on comple te retinal tumor control, vitreous seed control, and subretinal seed c ontrol. Design: The study design was a prospective, nonrandomized clin ical trial. Participants: There were 130 intraocular retinoblastomas i n 52 eyes of 32 consecutive patients observed for at least 1 year afte r initiation of treatment. Intervention: Treatment with chemoreduction using vincristine, etoposide, and carboplatin (VEC) and adjuvant trea tment (+ AT) (cryotherapy, laser photocoagulation, thermotherapy, chem othermotherapy, plaque radiation therapy, or external beam radiation t herapy) were assessed. Main Outcome Measures: The effect of chemoreduc tion for 6 cycles (VEC x 6) versus fewer than 6 cycles (VEC x < 6) on retinoblastoma control was analyzed. Furthermore, the impact of adjuva nt treatment (+ AT) versus no adjuvant treatment (no AT) on retinoblas toma control was analyzed. Results: Retinal tumors showed favorable in itial regression with chemoreduction. Adjuvant treatment was applied t o 93% of the retinal tumors after chemoreduction and only 2% recurred over the mean follow-up of 17 months (range 13-27 months). Vitreous se eds and subretinal seeds showed initial regression and often complete disappearance with chemoreduction. In those eyes with seeds before tre atment, the addition of AT to VEC for 6 cycles decreased the vitreous seed recurrence from 75% to 0% (P = 0.04) and also decreased the subre tinal seed recurrence from 67% to 0% (P = 0.003). More important, when considering that enucleation or external beam radiation therapy was t he only other treatment option for these 52 eyes, the authors were suc cessful in avoiding these methods in 42% of cases. Of the 36 eyes clas sified as Reese-Ellsworth group 5, there was 78% ocular salvage, and e xternal beam radiation therapy was avoided in 25% of these eyes. There was a 100% ocular salvage in the group 5 eyes that received VEC for 6 cycles + AT to retinal tumors and seeds. Conclusions: Chemoreduction and AT to intraocular retinoblastoma and its seeds provides good retin al tumor control, even in eyes with advanced disease. Chemoreduction a lone generally is not adequate to achieve complete tumor seed control. Cautious follow-up of affected patients is recommended because the ri sk for recurrent vitreous and subretinal seeds is substantial and prop er treatment is critical for salvaging the eye.