Memory function in disease-free survivors of childhood acute lymphocytic leukemia given CNS prophylaxis with or without 1,800 cGy cranial irradiation.

Previous studies have found that CNS prophylaxis of children with leukemia, especially young children receiving cranial irradiation, causes neuropsychologic deficits. In the present study, 40 children in continuous complete remission from acute lymphocytic leukemia (ALL) were given a battery of tests to assess memory functioning 5 years after CNS prophylaxis. All children were free of CNS disease at diagnosis and had been randomly assigned to receive CNS prophylaxis with either 1,800 cGy cranial irradiation (CRT) plus intrathecal (IT) methotrexate (MTX) or IT MTX plus intravenous (IV) high-dose MTX (HDMTX). No treatment- or age-related differences were seen on 16 standardized memory measures. However, scores of the combined sample were significantly lower than age-corrected norms on a test of visual-spatial memory and on four scales of verbal memory. Differences in methods or intensity of CNS prophylaxis and study group selection criteria are proposed to explain our findings and to resolve discrepancies with previous reports. The long-term neuropsychological sequelae in these survivors of ALL may be attributable to some common factor, such as the disease itself or systemic and IT chemotherapy.