To avoid the severe irradiation-related neurotoxic effects of postoperative treatment of malignant brain tumors in infants and children less than 3 years of age, the Pediatric Oncology Group, centered at St Louis, MO, conducted a prospective study of primary postoperative chemotherapy. Treatment consisted of two 28-day cycles of cyclophosphamide plus vincristine, followed by one 28-day cycle of cisplatin plus etoposide. The sequence was repeated 1) until the tumor showed progression or 2) for 2 years in 132 children < 24 months of age at diagnosis and 3) for 1 year in 66 children of 24-36 months of age. Chemotherapy was then followed by radiation. The first two treatment cycles produced complete or partial responses in 39% of 102 patients evaluated. Medulloblastomas, malignant gliomas, and ependymomas were most responsive, whereas brain-stem gliomas or embryonal tumors showed little or no response. The progression-free survival was 40% at the completion of treatment schedules. Cognitive evaluations at base line and after 1 year of chemotherapy showed no deterioration. 
COMMENT. Chemotherapy prevents disease progression and permits radiation therapy to be delayed for one to two years in about 40% of infants and very young children with malignant brain tumors. The best results are obtained in those with total surgical resection of localized disease. Chemotherapy is least effective in children with embryonal, primitive neuroectodermal tumors. Dr JC Allen, New York University Medical Center, cautions that delaying cerebral radiotherapy for 1 to 2 years may not spare an infant neurocognitive complications, and that intensive chemotherapy may also prove to have a detrimental effect on brain development.