Dutch Childhood Leukemia Study Group: Early Results of Study ALL VI (1984–1988)

The Dutch Childhood Leukemia Study Group (DCLSG) protocol ALL VI was designed as a nationwide study to treat children with non-high-risk acute lymphoblastic leukemia (ALL) in a uniform protocol. More than 98% of all children with leukemia in the Netherlands are registered by the DCLSG [1]. Previous protocols in the Netherlands used cranial irradiation as CNS prophylaxis [2]. Since long-term risks for cerebral function became apparent, in study ALL VI cranial irradiation has been replaced by three courses of medium-dose methotrexate (MDMTX; 2 g/m2) combined with intrathecal MTX, followed by seven intrathecal injections with triple chemotherapy [MTX, cytosine arabinoside (ARA-C), prednisolone] [3, 4]. Furthermore, oral administration of dexamethasone was used instead of prednisone since data became available that this resulted in a lower incidence of meningeal relapse [5]. The feasibility of this treatment was first evaluated in a pilot study, which, however, still employed prednisone instead of dexamethasone.