Minor changes on cranial MRI during treatment in children with acute lymphoblastic leukaemia.

Cranial MRI was used to study treatment-related changes in children undergoing therapy for acute lymphoblastic leukaemia (ALL) or lymphoma. Nineteen children (18 with ALL, 1 with lymphoma) underwent MRI at the beginning of treatment and at intervals during it, to a total of 105 imaging studies and a minimum of 3 per case. Nine patients had finished all therapy, all received consolidation treatment. No patient had central nervous system (CNS) leukaemia at diagnosis or developed a CNS relapse. Mild treatment-related white matter changes were observed in only 2 patients after consolidation therapy with three 5 g/m2 pulses of intravenous methotrexate. Transient enlargement of the ventricles and cortical sulci was observed in 13 patients, always temporally related to steroid treatment. These preliminary data suggest that treatment-related white matter changes are rare and no routine MRI follow-up is needed during treatment in asymptomatic children after a baseline assessment.