Diffusion-Weighted MR Imaging of Early Methotrexate-Related Neurotoxicity in Children

• Published in: American Journal of Neuroradiology 2005-08, Vol.26 (7), p.1686-1689
• Main Authors: Fisher, Michael J, Khademian, Zarir P, Simon, Erin M, Zimmerman, Robert A, Bilaniuk, Larissa T
• Format: Article
• Language: English
• Subjects: Adolescent; Antimetabolites, Antineoplastic - adverse effects; Antimetabolites, Antineoplastic - therapeutic use; Aphasia - etiology; Biological and medical sciences; Brain - pathology; Brain Diseases - chemically induced; Brain Diseases - diagnosis; Child; Diffusion Magnetic Resonance Imaging; Female; Follow-Up Studies; Fundamental and applied biological sciences. Psychology; Hematologic Neoplasms - complications; Hematologic Neoplasms - drug therapy; Hematologic Neoplasms - psychology; Hemiplegia - etiology; Human; Humans; Investigative techniques, diagnostic techniques (general aspects); Learning; Learning. Memory; Male; Medical sciences; Methotrexate - adverse effects; Methotrexate - therapeutic use; Nervous system; Nervous system (semeiology, syndromes); Nervous system as a whole; Neurology; Neurotoxins; Pediatrics; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Radiodiagnosis. Nmr imagery. Nmr spectrometry
• ISSN: 0195-6108; 1936-959X; 1432-1920

Methotrexate is a major cause of treatment-related acute neurotoxicity in children with hematologic malignancies. The purpose of this study was to investigate whether diffusion-weighted MR imaging (DWI) detects acute methotrexate white matter neurotoxicity in this patient population. Six children-three female and three male-with hematologic malignancies were studied at time of onset of neurologic dysfunction during the delayed intensification or consolidation phase of therapy, when intensive intrathecal methotrexate is given. MR imaging including DWI was performed on 1.5 T MR scanners. DWI demonstrated abnormal restriction of motion of water in the centrum semiovale in all six patients. This finding correlated to the acute onset of hemiparesis or aphasia. Fluid-attenuated inversion recovery imaging was not positive at this time, but it was positive in all five patients in whom follow-up imaging was performed. Early detection of methotrexate white matter injury by DWI has the potential to alert the oncologist to this event and provide a technique by which treatment of neurotoxicity can be monitored.