[Which is the best methotrexate schedule for maintenance therapy of childhood ALL? A randomized study]

58 children were admitted to a prospective randomized leukemia induction and CNS-prophylaxis three different protocols were followed for maintenance. A (n = 20): 6-MP (50 mg/m2) p.o. daily + MTX (20-30 mg/m2) p.o. weekly; B (n = 20): 6-MP (50 mg/m2) p.o. daily + MTX (75-150 mg/m2) i.v. every two weeks; C (n = 18): 6-MP (50 mg/m2) p.o. daily + alternating 8-week-courses of four biweekly i.v. injections of MTX (75-150 mg/m2) and four biweekly i.v. injections of Cyclo (600 mg/m2). After all patients have been followed for at least 48 months, the rates of continuous complete remission are 42% in protocol A, 63% in protocol B, and 29% in protocol C. No encephalopathies have been observed with regimen B.