Abstract
Effects of chemoimmunotherapy, including cranial irradiation for central nervous system (CNS) -directed therapy, on children with acute lymphoblastic leukemia (ALL) were investigated. Fifty-six children with ALL in continuous complete remission (> 5 yr) and without evidence of current or past CNS diseases were evaluated in this retrospective study. Using standard measures of intelligence quotient (IQ), we repeatedly (1-4 times/person) evaluated IQ in the cohort of patients for the mean follow-up time of 10.1 yr, ranging from 5.1 to 15.5 yr. The 56 patients received a total number of 121 IQ testings and 42 patients received them more than twice. They were examined periodically at intervals of 1.4 to 10.0 yr (mean 4.5 yr) following diagnosis. This report confirms and extends the previous findings : decreased IQ was related to the younger age at the time of diagnosis and irradiation (<5 yr of age at diagnosis), the longer irradiation-examination interval, and female sex. Further longterm follow-up study is needed in these groups, since their IQ is still on the decline even after 10 yr of diagnosis.
