EE-4A REGIMEN (high-risk, stage I-II unilateral WT with contralateral NR or predisposition syndrome or diffuse hyperplastic perilobar NRs [DHPLNR]): Patients receive vincristine sulfate IV over 1 minute on days 1, 8, 15, 22, 29, and 36 (weeks 1-6) and dactinomycin IV over 1-5 minutes on days 1 and 22 (weeks 1 and 4).