The value of maintenance therapy following treatment of central nervous system leukemia.

The efficacy of intrathecal (IT) maintenance chemotherapy following central nervous system (CNS) leukemia was demonstrated in a retrospective study of 77 such episodes. The median durations of CNS and bone marrow (BM) remissions were significantly longer for the 41 maintained episodes (10+ and 9.5 months, respectively) compared with the 36 unmaintained episodes (4 and 2 months, respectively). Patients were comparable in each of these two groups. For those patients receiving maintenance therapy, there appeared to be an advantage in using four or more doses of IT medications for treatment of CNS leukemia, regardless of the number of doses necessary to clear the cerebrospinal fluid (CSF).