title: Relative cerebral blood volume measurements of low-grade gliomas predict patient outcome in a multi-institution setting.
abstract: OBJECTIVE
  The prognostic value of defining subcategories of gliomas is still controversial. This study aims to determine the utility of relative cerebral blood volume (rCBV) in predicting clinical response in patients with low-grade glioma at multiple institutions.
  
  
  METHODS
  Sixty-nine patients were studied with dynamic susceptibility contrast-enhanced perfusion MRI at two institutions. The pathologic diagnoses of the low-grade gliomas were 34 astrocytomas, 20 oligodendroglioma, 9 oligoastrocytomas, 1 ganglioglioma and 5 with indeterminate histology. Wilcoxon tests were used to compare patients in different response categories with respect to baseline rCBV. Kaplan-Meier curve and log-rank tests were used to predict the association of rCBV with time to progression.
  
  
  RESULTS
  At both institutions, patients with an adverse event (progressive disease or death) had a significantly higher baseline rCBV than those without (complete response or stable disease) (p value=0.0138). The odds ratio for detecting an adverse event when using rCBV was 1.87 (95% confidence interval: 1.14-3.08). rCBV was significantly negatively associated with time to progression (p=0.005). The median time to progression among subjects with rCBV>1.75 was 365 days, while there was 95% confidence that the median time to progression was at least 889 days among subjects with rCBV<1.75.
  
  
  CONCLUSIONS
  Our study suggests not only that rCBV measurements correlate well with time to progression or death, but also that the findings can be replicated across institutions, which supports the application of rCBV as an adjunct to pathology in predicting glioma biology.
authors.affiliation: Institute of Neurology, UCL, London SW1X 0HZ, UK. g.brasil@ion.ucl.ac.uk
authors.forename: Gisele B
authors.initials: GB
authors.lastname: Caseiras
authors.forename: Sophie
authors.initials: S
authors.lastname: Chheang
authors.forename: James
authors.initials: J
authors.lastname: Babb
authors.forename: Jeremy H
authors.initials: JH
authors.lastname: Rees
authors.forename: Nicole
authors.initials: N
authors.lastname: Pecerrelli
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Tozer
authors.forename: Christopher
authors.initials: C
authors.lastname: Benton
authors.forename: David
authors.initials: D
authors.lastname: Zagzag
authors.forename: Glyn
authors.initials: G
authors.lastname: Johnson
authors.forename: Adam D
authors.initials: AD
authors.lastname: Waldman
authors.forename: H R
authors.initials: HR
authors.lastname: Jäger
authors.forename: Meng
authors.initials: M
authors.lastname: Law
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001811:Blood Volume Determination / Q000295:instrumentation / Q000706:statistics & numerical data*; D001921:Brain / Q000473:pathology*; D001932:Brain Neoplasms / Q000401:mortality*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005910:Glioma / Q000401:mortality* / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D009518:New York / Q000453:epidemiology; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D015996:Survival Rate; D006113:United Kingdom / Q000453:epidemiology; D055815:Young Adult