Chemoreduction for unilateral retinoblastoma.

OBJECTIVE: To evaluate conservative management of unilateral retinoblastoma using chemoreduction and focal treatment.
DESIGN: Prospective nonrandomized single-center clinical trial.
SETTING: Ocular Oncology Service at Wills Eye Hospital of Thomas Jefferson University, Philadelphia, Pa, in conjunction with the Division of Oncology at The Children's Hospital of Philadelphia. PARTICIPANTS: Thirty eyes of 30 patients with unilateral retinoblastoma treated with chemoreduction between June 1, 1994, and August 31, 1999, that would otherwise have been managed with enucleation or external beam radiotherapy. INTERVENTION: All patients received treatment for retinoblastoma with a planned 6 cycles of chemoreduction using vincristine sulfate, etoposide, and carboplatin, combined with focal treatment (cryotherapy or thermotherapy) to each retinal tumor. MAIN OUTCOME MEASURES: The main outcome measure was the postchemoreduction need for external beam radiotherapy or enucleation. The cumulative probability of each outcome was estimated using Kaplan-Meier survival analysis. A secondary outcome measure was final visual acuity in the affected eye. The clinical features at the time of patient presentation were analyzed for their impact on the main outcomes using a series of Fisher exact tests and Cox proportional hazards regressions.
RESULTS: Eighteen eyes (60%) were classified as having Reese-Ellsworth (RE) groups I through IV retinoblastoma and 12 eyes (40%), group V retinoblastoma. By using Kaplan-Meier estimates, we found a need for either external beam radiotherapy or enucleation in 68% of eyes by 5 years. In fact, 38% of those in groups I through IV required either treatment, whereas all of those in group V required the additional use of either treatment. Specifically, the need for external beam radiotherapy occurred in 27% of eyes by 5 years. Eleven percent of those in groups I through IV and 50% of group V required external beam radiotherapy by 5 years. The factors predictive of the need for external beam radiotherapy included RE group V disease, tumor thickness greater than 5 mm, and presence of vitreous seeds. The need for enucleation occurred in 47% of eyes by 5 years using Kaplan-Meier analysis. Specifically, 29% of those in groups I through IV and 67% of group V required enucleation by 5 years. The factors predictive of the need for enucleation included age at diagnosis older than 12 months, RE group V disease, tumor base diameter greater than 15 mm, and tumor thickness greater than 5 mm. At a mean follow-up of 29 months, the final visual acuity was 20/200 or better in 6 eyes (20%) and worse than 20/200 in 14 (47%); enucleation was needed in 10 (33%). Of the 26 eyes with initial macular involvement of retinoblastoma, final visual acuity was 20/200 or better in 6 (23%). No patient developed retinoblastoma metastasis, pinealoblastoma, or second malignant neoplasms.
CONCLUSIONS: Chemoreduction is an option for selected eyes with unilateral retinoblastoma. Those with advanced RE group V retinoblastoma showed poorest results, while those with less advanced groups I through IV disease showed best results, maintaining the globe in 71% of eyes, sometimes with satisfactory functional visual acuity.