Neuroimaging and neuropsychological follow-up study in a pediatric brain tumor patient treated with surgery and radiation

Abstract

Intracranial tumors are the most common neoplasms of childhood, accounting for approximately 20% of all pediatric malignancies. Radiation therapy has led directly to significant increases in survival of children with certain types of intracranial tumors; however, given the aggressive nature of this therapy, children are at risk for exhibiting changes in brain structure, neuronal biochemistry, and neurocognitive functioning. In this case report, we present neuropsychological, magnetic resonance imaging, proton magnetic resonance spectroscopic imaging, and diffusion tensor imaging data for two adolescents (one patient with ependymal spinal cord tumor with intracranial metastases, and one healthy, typically developing control) from three time points as defined by the patient's radiation schedule (baseline before the patient's radiation therapy, 6 months following completion of the patient's radiation, and 27 months following the patient's radiation). In the patient, there were progressive decreases in gray and white matter volumes as well as early decreases in mean N-acetyl aspartate/choline (NAA/Cho) ratios and fractional anisotropy (FA) in regions with normal appearance on conventional MRI. At the last follow-up, NAA/Cho and FA tended to change in the direction to normal values in selected regions. At the same time, the patient had initial reduction in language and motor skills, followed by return to baseline, but later onset delay in visuospatial and visual perceptual skills. Results are discussed in terms of sensitivity of the four techniques to early and late effects of treatment, and avenues for future investigations.

Keywords:

• Neuroimaging
• Neuropsychological
• Neoplasm
• Radiation
• Diffusion
• Magnetic resonance spectroscopy

A portion of this study was presented at the 34th Annual International Neuropsychological Society Conference, Boston, Massachusetts, February 4, 2006. The authors wish to thank Melissa Matson, Ph.D., David Bonekamp, M.D., Trisha Hay, Jena Peebles, and Mahaveer Degonkar, Ph.D., for their contribution to an earlier version of this work.

Supported by R01 NS04285, HD-24061 (Developmental Disabilities Research Center), P30HD024061-16, and Johns Hopkins University School of Medicine Institute for Clinical and Translational Research, an NIH/NCRR CTSA Program, UL1-RR025005.