Long-term neurological and neuropsychological outcome in 25 irradiated children <15-years of age and 25 treated with surgery alone for low-grade astrocytoma was evaluated by two neurosurgeons and two psychologists independently at the Royal Manchester Children’s Hospital, UK. Neurological function was not different in the irradiated group compared to the non-irradiated patients. In all neuropsychological tests used to assess intelligence, word reading, memory, learning and information processing, the performance of children with cranial radiation therapy was worse than those treated by surgery alone, and significant changes occurred in tests of IQ and information processing. Special education was required more frequently in the irradiated group. Both supratentorial tumor radiotherapy and local field irradiation to the posterior fossa for cerebellar tumors produced significant cognitive impairments. 
COMMENT. This study confirms previous reports of cognitive impairments following irradiation for supratentorial tumors in children. Additionally, even local field irradiation to the posterior fossa can result in learning and academic problems. Children receiving cranial radiation therapy, locally or to the whole brain, should be followed with neuropsychological testing for longer than 3 years to determine effects on IQ and the need for special education.