CLINICAL OBSERVATIONS, INTERVENTIONS, AND THERAPEUTIC TRIALS Intensive Treatment of Children With Acute Lymphoblastic Leukemia According to ALL-BFM-86 Without Cranial Radiotherapy: Results of Dutch Childhood Leukemia Study Group Protocol ALL-7 (1988-1991)

16 years of age) with de novo acute lymphoblastic leukemia (ALL) were treated according to protocol ALL-7 of the Dutch Childhood Leukemia Study Group (DCLSG). In this protocol, chemotherapy and treatment stratification were identical to the ALL-BFM-86 protocol (Reiter et al, Blood 84:3122, 1994), but cranial irradiation was restricted to patients with initial central nervous system (CNS) involvement. Patients were stratified into 3 risk groups, based on leukemia cell mass and response to initial treatment: standard-risk group (SRG), risk group (RG), and experimental group (EG). As in ALL-BFM-86, a randomized study on late intensification (protocol S) was performed in RG pa-tients, and during the study (since October 1990), early reinduc-tion treatment (protocol II) was introduced for SRG patients. Treatment duration for all patients was 18 months. Two hundred eighteen children entered the study: 74 SRG, 127 RG, and 17 E