[Late sequelae of CNS recurrence of acute lymphoblastic leukemia in childhood]

Study objective was to evaluate retrospectively central nervous system (CNS) morbidity of children with acute lymphoblastic leukemia treated with intensive chemotherapy and cranial radiotherapy for a first isolated or combined CNS relapse. Neurological (Touwen), neuropsychological (CFT 20, Wechsler scales, d2 attention test) and neuromorphological (CT, MRI) assessments were performed in 17 children (9 girls, 8 boys) aged between 7 and 14 years. Patients were off therapy for median 4 years; cranial radiotherapy for CNS relapse (12-24 Gy) was given to all patients 2 to 9 years ago (median 5.5 years). Ten patients had received preventive cranial radiotherapy during front-line treatment, previously. In this group, the cumulative radiation dose ranged between 30 and 39 Gy. Patients received 12 to 30 intrathecal methotrexate doses (median 22). Compared with normative levels for age (100 points) performance IQ (89.9) and full scale IQ (92.0), Culture Fair IQ (88.3) and attention and concentration (90.9) were significantly impaired. Verbal IQ (95.5) was not significantly different from normal expectations. Neurological investigations of 16 patients showed mild signs in 7 (44%) of them, mostly of fine-motor skills and coordination, but no major motor disability. In MRI and CT, white matter changes or ventricular enlargement were noted in 10 of 16 patients (63%). Parent-completed questionnaires indicated problem behaviors in 5 children. Cumulative doses of methotrexate correlated significantly with neuropsychological test results. Children irradiated twice as well as girls had poorer cognitive functions, not being statistically significant. Despite pathological test results, all children attended a normal school and did not exhibit obvious impairment in daily life. In conclusion, CNS relapse and attendant therapy, mostly consisting of a second course of cranial radiotherapy, caused measurable intellectual deficits and CNS morbidity, which did not result in severely impaired performance. Periodic psychological und clinical examinations are recommended for recognition of delayed morbiditiy and early intervention.