NEUROPSYCHOLOGICAL EFFECTS OF CRANIAL IRRADIATION IN YOUNG-CHILDREN WITH ACUTE LYMPHOBLASTIC-LEUKEMIA 9 MONTHS AFTER DIAGNOSIS

Study Objective: To determine the effects of cranial irradiation on ne uropsychological test performance evident 9 months after diagnosis. De sign: A companion study to a randomized clinical trial (CCG-105). Sett ing: Institutions participating in Childrens Cancer Group cooperative treatment trials. Patients: Seventy-four children aged 3.0 to 6.5 year s with average-risk acute lymphoblastic leukemia. Children with centra l nervous system leukemia at the time of diagnosis, preexisting mental retardation, or Down's syndrome or for whom English was not the prima ry language were not eligible for study. Interventions: Children were randomized to receive treatment with one of four systemic chemotherapy regimens and either intrathecal methotrexate sodium during induction and consolidation plus 18 Gy of cranial irradiation or intrathecal met hotrexate during induction, consolidation, and maintenance as central nervous system prophylaxis. Measurement and Results: The groups were c omparable with regard to chronologic age, sex, and family socioeconomi c status. Children who received cranial irradiation plus intrathecal m ethotrexate scored significantly lower on the McCarthy Motor Scale (P< .05) and the Token Test (P<.05) than children who received intrathecal methotrexate alone. The groups did not differ significantly on the Mc Carthy General Cognitive Index, Developmental Test of Visual Motor Int egration, or Pea-body Picture Vocabulary Test-Revised. Conclusions: Fi ndings suggest that the combined effects of cranial irradiation and in trathecal methotrexate therapy on neuropsychological performance may b e evident in young children as early as 9 months after diagnosis. Foll ow-up assessment of these children will reveal whether these effects r emain constant, intensify, or resolve.