Differences in supratentorial damage of white matter in pediatric survivors of posterior fossa tumors with and without adjuvant treatment as detected by magnetic resonance diffusion tensor imaging.
OBJECTIVE
To elucidate morphologic correlates of brain dysfunction in pediatric survivors of posterior fossa tumors by using magnetic resonance diffusion tensor imaging (DTI) to examine neuroaxonal integrity in white matter.


METHODS
Seventeen medulloblastoma (MB) patients who had received surgery and adjuvant treatment, 13 pilocytic astrocytoma (PA) patients who had been treated only with surgery, and age-matched healthy control subjects underwent magnetic resonance imaging on a 3-Tesla system. High-resolution conventional T1- and T2-weighted magnetic resonance imaging and DTI data sets were obtained. Fractional anisotropy (FA) maps were analyzed using tract-based spatial statistics, a part of the Functional MRI of the Brain Software Library.


RESULTS
Compared with control subjects, FA values of MB patients were significantly decreased in the cerebellar midline structures, in the frontal lobes, and in the callosal body. Fractional anisotropy values of the PA patients were not only decreased in cerebellar hemispheric structures as expected, but also in supratentorial parts of the brain, with a distribution similar to that in MB patients. However, the amount of significantly decreased FA was greater in MB than in PA patients, underscoring the aggravating neurotoxic effect of the adjuvant treatment.


CONCLUSIONS
Neurotoxic mechanisms that are present in PA patients (e.g., internal hydrocephalus and damaged cerebellar structures affecting neuronal circuits) contribute significantly to the alteration of supratentorial white matter in pediatric posterior fossa tumor patients.
Rueckriegel
Stefan Mark
SM
Department of Pediatric Oncology and Hematology, Charité-Universitätsmedizin Berlin, Berlin, Germany. stefan.rueckriegel@charite.de
Driever
Pablo Hernáiz
PH
Blankenburg
Friederike
F
Lüdemann
Lutz
L
Henze
Günter
G
Bruhn
Harald
H
D000293:Adolescent; D016880:Anisotropy; D001254:Astrocytoma / Q000473:pathology / Q000601:surgery; D001369:Axons; D001921:Brain / Q000187:drug effects / Q000473:pathology* / Q000528:radiation effects; D016022:Case-Control Studies; D002531:Cerebellum / Q000187:drug effects / Q000473:pathology / Q000528:radiation effects; D017024:Chemotherapy, Adjuvant / Q000009:adverse effects; D002648:Child; D002675:Child, Preschool; D016371:Cranial Irradiation / Q000009:adverse effects; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D015192:Infratentorial Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D056784:Leukoencephalopathies / Q000209:etiology / Q000473:pathology; D008297:Male; D008527:Medulloblastoma / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects; D017741:Survivors