One hundred and fifty-one children with acute lymphocytic leukaemia (ALL) received multiple agent induction chemotherapy followed by intensive phase treatment. One hundred and thirty-seven patients were randomised for the first year of maintenance treatment to receive reinforcement therapy (pulses) with either intermediate-dose methotrexate (ID-MTX) and prednisone (PRED) or vincristine (VCR) and PRED. The probability of continuous complete remission (CCR) at 5.5 years is 0.80 for the ID-MTX group and 0.84 for the VCR group. Extramedullary relapses were not prevented either in the ID-MTX group nor in the VCR group. Since in previous studies VCR/PRED pulses did not increase CCR rates when given after intensive combination chemotherapy, it can be concluded from this study that neither did ID-MTX reinforcement therapy further improve treatment results in our patients with ALL when given after aggressive chemotherapy.
