Treatment of overt meningeal leukaemia in children: results of second MRC meningeal leukaemia trial.

After induction ofmeningeal remission by a course of intrathecal methotrexate patients were randomly allocated to receive either cranial irradiation or craniospinal irradiation. Patients being treated for their first meningeal relapse were randomised separately from those in their second or subsequent relapse. All eight patients in their first relapse who were given cranial irradiation alone developed further meningeal recurrence (median length of remission 15 weeks) compared with only two out of nine given craniospinal irradiation (median length of remission at least 99 weeks). Four of the nine patients given craniospinal irradiation were alive and without further meningeal relapse two and a half to four years after treatment. Craniospinal irradiation produced no such advantage for patients entering the trial in their second or subsequent meningeal relapse.