Risk factors for intellectual and educational sequelae of cranial irradiation in childhood acute lymphoblastic leukaemia

Abstract

Summary Long-term cognitive and educational sequelae have been inconsistently reported in children who received cranial irradiation (CRT) to prevent central nervous system (CNS) disease in acute lymphoblastic leukaemia (ALL). This study investigates a large and representative sample of survivors of ALL and compares them with non-irradiated survivors of cancer and healthy control children to determine the effect of CRT on cognitive and educational ability. Three groups of children were studied: Group 1 (n= 100) survivors of ALL treated with chemotherapy and CRT, group 2 (n = 50) children with a variety of malignancies treated with chemotherapy alone, group 3 (n = 100) healthy children. Cognitive and educational abilities of these groups were evalutated using standardised psychometric techniques. Significant differences in cognitive and educational abilities were found between the children in group 1 (chemotherapy + CRT) and the two control groups, with the children receiving CRT performing less well in a range of tests. Greatest differences were detected for tasks dependent on language function including verbal IQ, reading and spelling. Within group 1 a younger age at treatment (less than 5 years) and a higher dose of CRT (24 Gy vs 18 Gy) were predictive of poor long-term outcome for cognitive and education ability. In contrast, children who received chemotherapy alone, with or without intrathecal methotrexate, performed similarly to healthy controls. No gender differences were detected for these measures.

Neurodevelopmental sequelae of pediatric acute lymphoblastic leukemia and its treatment

“…Intellectual outcomes were generally better for children treated with 1,800 cGy than 2,400 cGy [Moore et al, 1991;Halberg et al, 1992;Smibert et al, 1996], although this was not a consistent finding Rodgers et al, 1991;Waber et al, 1995]. Significant correlations have been documented between higher CR dose and lower cognitive performance [Kingma et al, 1993].…”

Quality of Life and Cognitive Function in Patients with Pituitary Insufficiency

“…in childhood leukaemia [33], 25 studies are cited that report negative effects of irradiation on cognitive meaAlthough the underlying mechanisms of irradiationinduced neurocognitive dysfunction are not yet fully unsurements. Other studies indicate that children who receive CRT develop impaired visual and verbal memory, derstood, present evidence indicates that CRT may induce neurocognitive dysfunction, younger children being the attention capacity, verbal fluency, and visual discrimination skills, verbal IQ, and reading and spelling [34,35]. most susceptible to these injuries.…”

Lack of benefit of spinal irradiation in the primary treatment of intracranial germinoma

“…31,[33][34][35][36] Clinical experience involving patients suffering from leukemia who received prophylactic cranial irradiation showed that the incidence of intellectual deficits in patients younger than 6 or 8 years of age was higher than that in older subjects. 35,36 Fortunately, intracranial germinomas usually arise in patients older than 8 years of age. In the current study, only 6 (4%) patients were younger than 8 years of age.…”