Intraventricular versus intralumbar methotrexate for central‐nervous‐system leukemia: Prolonged remission with the ommaya reservoir

Ten children had recurrence of central-nervous-system (CNS) leukemia despite monthly injections of methotrexate into their lumbar cerebrospinal fluid. Each child was then reinduced into remission and maintained with intraventricular methotrexate administered via an Ommaya reservoir and the length of this remission was compared with the duration of the child's previous intralumbar-treated remission. Of eight evaluable patients, seven had longer CNS remissions with intraventricular therapy than with intralumbar therapy (P less than 0.02). The median CNS remission duration in all patients was 475 days with intraventricular and 286 days with intralumbar therapy (P less than 0.05). The rate of CNS relapse was reduced from 2.94 relapses per thousand days at risk during intralumbar therapy to 0.93 relapse per thousand days of intraventricular therapy. We conclude that intraventricular chemotherapy is significantly more effective against CNS leukemia than the same therapy given by lumbar puncture.