Remission maintenance therapy for meningeal leukaemia: intrathecal methotrexate and dexamethasone versus intrathecal craniospinal irradiation with a radiocolloid.

Thirty-two patients with meningeal leukaemia who achieved meningeal remission with intrathecal methotrexate (MTX) plus dexamethasone (DMT) were entered in a randomized study of two maintenance treatments: (a) I6 patients received intermittent intrathecal doses of MTX plus DMT, and (b) I6 patients received intermittent intrathecal doses of radioactive chromic phosphate (CROP). The population and clinical characteristics of the cases assigned to each maintenance regimen were similar. The duration of meningeal remission was 55-600 + d (median 550 d) for the MTX and DMT group and 56-555 d (median 360 d) for the CROP group. There was no statistical difference (P greater than 0.05) between the curves of the two groups. Intrathecal CROP seems to be as effective as intrathecal MTX plus DMT as maintenance treatment for intrathecal MTX plus DMT induced meningeal remission. Further uses of this compound should be explored but it seems to be dangerous to administer it by lumbar puncture.