The survival rate and cognitive function of 43 children, age <3 years, with medulloblastoma treated with intensive postoperative chemotherapy alone, without radiotherapy, were determined at the University of Wurzburg and other centers in Germany Chemotherapy consisted of three two-month cycles of cyclophosphamide, methotrexate, vincristine, carboplatin, and etoposide. Intraventricular methotrexate was also administered in 36 doses through an implanted subcutaneous reservoir, beginning 2 to 4 weeks after surgery. The five-year progression-free and overall survival rates (+/-SE) were 82+/-9% and 93+/-6% for 17 patients with complete resection, 50+/-13% and 56+/-14% for 14 with residual tumor, 33+/-14% and 38+/-15% for 12 with macroscopic metastases, and 68+/-8% and 77+/-8% in 31 patients without macroscopic metastases. Tumor relapse occurred in 9 of 29 patients without residual disease after chemotherapy. Independent risk factors for tumor relapse were desmoplastic form of medulloblastoma (20 patients), metastatic disease, and age younger than 2 years. Asymptomatic leukoencephalopathy was detected by MRI in 19 of 23 patients. After treatment with chemotherapy, the mean IQ was significantly lower than that of healthy controls of the same age but higher than that of patients treated by radiotherapy in a previous trial. 
COMMENT. Intensive postoperative chemotherapy that includes intraventricular methotrexate provides long remissions in children with medulloblastoma, and results are especially promising for patients without initial metastases. Except in cases of relapse, radiotherapy with its adverse side effects may be avoided in the very young patient with medulloblastoma.