title: Dynamic contrast-enhanced magnetic resonance imaging as a biomarker for prediction of radiation-induced neurocognitive dysfunction.
abstract: OBJECTIVE
  To determine whether early assessment of cerebral microvessel injury can predict late neurocognitive dysfunction after brain radiation therapy (RT).
  
  
  METHODS
  Ten patients who underwent partial brain RT participated in a prospective dynamic contrast-enhanced magnetic resonance imaging (MRI) study. Dynamic contrast-enhanced MRI was acquired prior to, at weeks 3 and 6 during, and 1 and 6 months after RT. Neuropsychological tests were done pre-RT and at the post-RT MRI follow-ups. The correlations between early delayed changes in neurocognitive functions and early changes in vascular variables during RT were analyzed.
  
  
  RESULTS
  No patients had tumor progression up to 6 months after RT. Vascular volumes and blood-brain barrier (BBB) permeability increased significantly in the high-dose regions during RT by 11% and 52% (P<0.05), respectively, followed by a decrease after RT. Changes in both vascular volume and BBB permeability correlated with the doses accumulated at the time of scans at weeks 3 and 6 during RT and 1 month after RT (P<0.03). Changes in verbal learning scores 6 months after RT were significantly correlated with changes in vascular volumes of left temporal (P<0.02) and frontal lobes (P<0.03), and changes in BBB permeability of left frontal lobes during RT (P<0.007). A similar correlation was found between recall scores and BBB permeability.
  
  
  CONCLUSIONS
  Our data suggest that the early changes in cerebral vasculature may predict delayed alterations in verbal learning and total recall, which are important components of neurocognitive function. Additional studies are required for validation of these findings.
authors.affiliation: Radiation Oncology, University of Michigan, and VA Ann Arbor Healthcare System, Ann Arbor, Michigan 48109-0010, USA. yuecao@umich.edu
authors.forename: Yue
authors.initials: Y
authors.lastname: Cao
authors.forename: Christina I
authors.initials: CI
authors.lastname: Tsien
authors.forename: Pia C
authors.initials: PC
authors.lastname: Sundgren
authors.forename: Vijaya
authors.initials: V
authors.lastname: Nagesh
authors.forename: Daniel
authors.initials: D
authors.lastname: Normolle
authors.forename: Henry
authors.initials: H
authors.lastname: Buchtel
authors.forename: Larry
authors.initials: L
authors.lastname: Junck
authors.forename: Theodore S
authors.initials: TS
authors.lastname: Lawrence
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D001812:Blood-Brain Barrier; D001932:Brain Neoplasms / Q000503:physiopathology / Q000532:radiotherapy*; D002560:Cerebrovascular Circulation / Q000528:radiation effects; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology; D003287:Contrast Media; D004305:Dose-Response Relationship, Drug; D005260:Female; D019786:Gadolinium DTPA; D005910:Glioma / Q000503:physiopathology / Q000532:radiotherapy*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011446:Prospective Studies; D011832:Radiation Injuries / Q000175:diagnosis* / Q000209:etiology; D011878:Radiotherapy / Q000009:adverse effects*; D020266:Radiotherapy, Conformal
chemical_list: D014408:Biomarkers, Tumor; D003287:Contrast Media; D019786:Gadolinium DTPA