Long-term follow-up of brain tumors in childhood after radiotherapy

An increase in the survival rate of children with brain tumors has produced a new problem: the late impairment effects of radiotherapy on intelligence. We conducted a follow-up study of intelligence levels in a total of 23 children who had tumors with a relatively good prognosis, i.e., craniopharyngioma, germinoma, and cerebellar astrocytoma. The cases were aged 1-14 years, and the period of follow-up was 3-15 years. Intellectual development was categorized depending on the situation of school attendance, and was evaluated on a 5-point scale. As radiation to the posterior fossa doesn't cause a big problem on intelligence, the cases of cerebellar astrocytoma were excluded. Of the remaining cases, 45% (7/16) were intellectually retarded. They were less than 11 years of age at the time of radiation. Three of those with especially severe impairment were less than 5 years old at the time of radiation. We need to think about the influence of radiation on intelligence in childhood, although we can't exclude other factors influencing intelligence. (author)