The effects of radiotherapy on the neuropsychological functioning of children treated for brain tumors

Among children with brain tumors, many factors have been associated with declines in intellectual and neuropsychological functioning, but few researchers have examined the joint effects of these variables. The present study used a regression model to evaluate the joint effects of age at diagnosis, XRT status (0 = NO XRT; 1 = XRT), and duration of illness among 78 pediatric brain tumor patients. The XRT treated group (N = 45) was tested at least one year after XRT therapy. Thirty-three nonirradiated patients made up the comparison group (NO XRT group). The groups were similar in demographic variables and tumor locations; however, the XRT group was older at evaluation (Mean XRT Test age = 11.5 years; Mean NO XRT Test age = 9 years) and had a longer duration of illness compared to the NO XRT group (Mean XRT Duration = 3.5 years; Mean NO XRT Duration = 9 months). Dependent variables were neuropsychological tests of similar functions combined to form 14 composite scores. Not all patients were administered the whole battery. The presence of XRT predicted lower scores on tests of verbal memory and fine-motor skills regardless of diagnosis age. A younger diagnosis age predicted lower composite scores on Performance IQ and visual-spatial skills regardless of XRT status. A comparison of correlations across groups revealed an interaction between diagnosis age and XRT. Diagnosis age was positively correlated with scores on Verbal IQ and language tests in the XRT group, but not in the NO XRT group. [...]Psychology, Department o