title: Cerebral white matter fractional anisotropy and tract volume as measured by MR imaging are associated with impaired cognitive and motor function in pediatric posterior fossa tumor survivors.
abstract: BACKGROUND
  Disease and therapy cause brain damage and subsequent functional loss in pediatric patients with posterior fossa tumors. Treatment-related toxicity factors are resection in patients with pilocytic astrocytoma (PA) and, additionally, cranio-spinal irradiation together with chemotherapy in patients with medulloblastoma (MB). We tested whether damage to white matter (WM) as revealed by diffusion tensor MR imaging (DTI) correlated with specific cognitive and motor impairments in survivors of pediatric posterior fossa tumors.
  
  
  METHODS
  Eighteen MB (mean age ± SD, 15.2 ± 4.9 y) and 14 PA (12.6 ± 5.0 y) survivors were investigated with DTI on a 3-Tesla-MR system. We identified fractional anisotropy (FA) of WM, the volume ratio of WM to gray matter and cerebrospinal fluid (WM/GM + CSF), and volume of specific frontocerebellar tracts. Ataxia was assessed using the International Cooperative Ataxia Rating Scale (ICARS), while the Wechsler Intelligence Scale for Children determined full-scale intelligence quotients (FSIQ). Amsterdam Neuropsychological Tasks (ANT) was used to assess processing speed. Handwriting automation was analyzed using a digitizing graphic tablet.
  
  
  RESULTS
  The WM/GM + CSF ratio correlated significantly with cognitive measures (IQ, P = 0.002; ANT baseline speed, P = 0.04; ANT shifting attention, P = 0.004). FA of skeletonized tracts correlated significantly with FSIQ (P = 0.008), ANT baseline speed (P = 0.028) and ANT shifting attention (P = 0.045). Moreover, frontocerebellar tract volumes correlated with both the FSIQ (P = 0.011) and ICARS (P = 0.007).
  
  
  CONCLUSIONS
  DTI provides a method for quantification of WM damage by tumor and by therapy-associated effects in survivors of pediatric posterior fossa tumors. DTI-derived WM integrity may be a representative marker for cognitive and motor deterioration.
authors: Pediatric Neurooncology Program, Department of Pediatric Oncology and Hematology, Charité-CVK, Berlin, Germany.|Department of Neurosurgery, University Hospital Würzburg, Würzburg, Germany.
authors: Stefan M
authors: SM
authors: Rueckriegel
authors: Department of Radiology, Charité-CVK, Berlin, Germany.
authors: Harald
authors: H
authors: Bruhn
authors: Section of Pediatric Neurosurgery, Charité- CVK, Berlin, Germany.
authors: Ulrich W
authors: UW
authors: Thomale
authors: Pediatric Neurooncology Program, Department of Pediatric Oncology and Hematology, Charité-CVK, Berlin, Germany.
authors: Pablo
authors: P
authors: Hernáiz Driever
mesh_terms: D000293:Adolescent; D016880:Anisotropy; D001254:Astrocytoma / Q000150:complications* / Q000473:pathology; D001259:Ataxia / Q000175:diagnosis* / Q000209:etiology; D002528:Cerebellar Neoplasms / Q000150:complications / Q000473:pathology; D002648:Child; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015192:Infratentorial Neoplasms / Q000150:complications* / Q000473:pathology; D007361:Intelligence Tests; D008297:Male; D008527:Medulloblastoma / Q000150:complications* / Q000473:pathology; D009483:Neuropsychological Tests; D011379:Prognosis; D015996:Survival Rate; D017741:Survivors; D066127:White Matter / Q000473:pathology*
keywords: DTI; diffusion tensor imaging; pediatric brain tumors; white matter integrity