Superiority of conventional intrathecal methotrexate therapy with maintenance over intensive intrathecal methotrexate therapy, unmaintained, or radiotherapy (2000-2500 rads tumor dose) in treatment for meningeal leukemia.

In the treatment of patients with meningeal leukemia, conventional intrathecal methotrexate therapy followed by maintenance intrathecal methotrexate at intervals of 8 weeks has been shown superior to an intensive, unmaintained intrathecal methotrexate induction regimen, and to neuroaxis radiotherapy, tumor dose 2000-2500 rads. In each of the treatment regimens, all children completing proscribed therapy achieved complete CNS remission as judged by the return of CSF findings to normal. Median lengths of remission were: maintenance regimen 240 days; intensive induction regimen, 106 days; and radiotherapy, 216 days. Differences were of statistical significance between the maintenance regimen and the intensive regimen (p equal 0.001), and between the radiotherapy and intensive regimens (p equal 0.01). Maintenance intrathecal therapy appeared to affect favorably the duration of existing marrow remissions; the median time to marrow relapse for patients given maintenance therapy was significantly longer than for those given intensive induction therapy. Toxicity of the chemotherapy regimens was not prohibitive. Radiotherapy was associated with severe myelosuppression, interruptions of systemic therapy, and serious infections, which resulted in death in five children.