Carboplatin therapy for optic pathway tumors in children with neurofibromatosis type-1

Symptomatic optic pathway tumors (OPT) occur in 7% of children with neurofibromatosis type-1 (NF-1). Although tumor progression following diagnosis is unusual in such children, specific therapy may be necessary for patients with either severe or progressive disease. We reviewed the records of 9 children (6 girls, 3 boys) with NF-1 associated OPT who were treated with the second generation platinum compound carboplatin. Carboplatin was given at a dose of 560 mg/mm² every 4 weeks for a mean of 15 cycles. The mean age at presentation of the OPT was 3.4 years. Eight children had abnormal ophthalmologic examinations at the time of diagnosis. Only 4 patients had documented evidence of progressive disease prior to the institution of therapy. No patient had evidence of progressive disease following therapy. Four patients had radiologic evidence of tumor shrinkage and 2 patients had definite improvement in vision. There was only minimal toxicity. In conclusion, carboplatin is a safe and effective treatment for OPT in children with NF-1. However, as disease stabilization of NF-1 associated OPT often occurs following clinical presentation, the clinician should document tumor progression or visual deterioration prior to the institution of therapy.