The role of magnetic resonance imaging in the diagnosis of central nervous system involvement in children with acute lymphoblastic leukemia.

Purpose Acute lymphoblastic leukemia (ALL) is the most frequent malignancy in childhood. As central nervous system (CNS) involvement requires an intensified CNS-targeted therapy, timely diagnosis is essential. The aim of this retrospective analysis was to evaluate whether cranial magnetic resonance imaging (MRI) examinations findings correlate with cerebrospinal fluid (CSF) analysis on CNS involvement and whether MRI examinations reveal incidental findings with a clinical consequence. Methods All pediatric patients with ALL at our institution between 1998 and 2016 were identified. Patients were divided into two groups: de novo and relapsed ALL. Both groups were analyzed separately for the presence of CNS involvement. Incidental findings were also evaluated. Results Two hundred fifteen patients with de novo ALL and 31 with relapsed ALL were identified. In the de novo group, no patient was diagnosed CNS positive based on MRI results alone. In relapsed patients, only one patient had a positive MRI with negative CSF results and no neurological symptoms, thus was classified CNS positive solely on the basis of the MRI. In both groups, no patient showed an incidental finding that required therapy. Conclusion In our study, MRI examinations do not improve the detection of CNS involvement compared with CSF analysis alone. In addition, the analysis of incidental findings does not add value to the performance of an MRI examination performed prior to treatment. Overall, MRI prior to treatment in pediatric patients with ALL is not necessary.