Long-term survivors of leukemia treated in infancy: factors associated with neuropsychologic status.

Purpose: Because of concerns about late toxicities of treatment among infants diagnosed with acute lymphoblastic leukemia (ALL), and especially the effects of cranial radiation therapy (CRT), we compared the functional and neuropsychologic status of 26 long-term survivors of ALL who were diagnosed in the first 24 months of life versus 26 children who were treated previously for Wilms' tumor.

Patients And Methods: Of the children with ALL, CNS prophylaxis included no CRT in six, 18 Gy CRT in five, 20 Gy CRT in seven, and 24 Gy CRT in five. Three additional children experienced CNS relapse and received total CRT doses of 24, 40, and 44 Gy. All children received neuropsychologic testing; children with ALL also participated in diagnostic imaging studies.

Results: As a group, the children who were treated for ALL did not differ significantly from those who were treated for Wilms' tumor on objective measures of global functional status. However, children treated for ALL had a significantly lower mean intelligence quotient (IQ) (87 v 96), poorer performance on four of six measures of visual and auditory memory, lower achievement with regard to arithmetic skills, and a greater frequency of special educational intervention than those who were treated for Wilms' tumor. IQ and auditory memory performance in the ALL group was correlated inversely with time since the completion of therapy and total CRT dose.

Conclusions: These results reinforce the contemporary trend of prophylactic CRT omission in very young children except for those who are at risk for CNS relapse. For infants and very young children who require CRT, evidence is presented that supports the approach for the delay of CRT until the child is older.