[Acute lymphoblastic leukemia of standard risk: preliminary results obtained with protocol LL-IV-81]

Forty-five patients with acute lymphoblastic leukemia of standard risk who were treated with the same protocol of therapy are presented. Induction therapy consisted of Vincristine (5 doses), L-asparaginase (10 doses) and prednisone. Complete remission was attained in 43 cases (95%). Two different methods of CNS prophylaxis were used; radiotherapy of the skull (18 Gy) associated with intrathecal methotrexate and intermediate dose intravenous methotrexate (1 g/M, 12 dose) with simultaneously intrathecal methotrexate. With a mean follow-up time of 28 months in group A and 35 Mo in group B, 82% and 75% respectively remain in continuous complete remission (p: NS). One case of meningeal leukemia was detected in each group. There patients in group A (13.6%) and four in group B (20%) suffered a bone marrow relapse. Actuarial survival rate at 36 months were 76 among the patients in group A and 83% in group B. Our results indicate that the two methods of CNS prophylaxis are both effective and in this series we have not observed any decrease in the bone marrow relapse rate when intermediate dose methotrexate was used.