Studies on the Use of "Prophylactic" Intrathecal Amethopterin in Childhood Leukemia

Central nervous system infiltration was studied in a group of 47 childrenwith acute leukemia. CNS involvement was found to occur more frequentlyand appear more rapidly in patients who presented with elevated peripheralWBC counts. CNS infiltration not suspected clinically was identified by spinalfluid examination in a significant minority of children at the time of theinitial diagnosis of leukemia, indicating that lumbar puncture should be aroutine part of the initial evaluation of patients with acute leukemia. Intrathecal amethopterin administered "prophylactically" at the time of initialdiagnosis of leukemia did not prevent or decrease the frequency of occurrenceof CNS infiltration. However, it did delay the onset of CNS involvement in patients with elevated WBC counts. Intrathecal amethopterin administered before the onset of CNS infiltration appears to be useful in delaying morbidityresulting from CNS involvement in children who present with elevated peripheral WBC counts.

Submitted on July 21, 1969 Revised on January 27, 1970 Accepted on February 10, 1970