title: Apparent diffusion coefficient obtained by magnetic resonance imaging as a prognostic marker in glioblastomas: correlation with MGMT promoter methylation status.
abstract: OBJECTIVE
  To evaluate whether apparent diffusion coefficient (ADC) values can predict the status of MGMT of glioblastoma multiforme (GBM) and correlate with overall survival (OS) and progression-free survival (PFS).
  
  
  METHODS
  This retrospective study included 47 patients with pathologically proven glioblastoma. All of them underwent MR DWI study before surgery (mean time 1 week) and the status of methylguanine-DNA-methyltransferase (MGMT) promoter methylation was searched for. Minimum apparent diffusion coefficient (ADC) values were evaluated. OS and PSF parameters were calculated, and Student's t-test, Kaplan-Meier curves, linear and Cox regression were performed.
  
  
  RESULTS
  Twenty-five patients showed positive methylation of the MGMT promoter. Patients showing MGMT promoter methylation had higher minimum ADC values, and they survived longer than those without MGMT promoter methylation. The median ADCmin value of 0.80 represents the cutoff value able to distinguish between methylated and un-methylated patients. Patients showing minimum ADC values higher than 0.80 survived longer than patients with minimum ADC values lower than 0.80. A linear correlation between minimum ADC values vs. the OS and PFS was observed.
  
  
  CONCLUSIONS
  Minimum ADC values in glioblastoma multiforme could be used as a preoperative parameter to estimate the status of MGMT promoter methylation and the survival of patients.
authors.affiliation: NESMOS, Department of Neuroradiology, S. Andrea Hospital, University Sapienza, Rome, Italy. andrea.romano@uniroma1.it
authors.forename: Andrea
authors.initials: A
authors.lastname: Romano
authors.forename: L F
authors.initials: LF
authors.lastname: Calabria
authors.forename: F
authors.initials: F
authors.lastname: Tavanti
authors.forename: G
authors.initials: G
authors.lastname: Minniti
authors.forename: M C
authors.initials: MC
authors.lastname: Rossi-Espagnet
authors.forename: V
authors.initials: V
authors.lastname: Coppola
authors.forename: S
authors.initials: S
authors.lastname: Pugliese
authors.forename: D
authors.initials: D
authors.lastname: Guida
authors.forename: G
authors.initials: G
authors.lastname: Francione
authors.forename: C
authors.initials: C
authors.lastname: Colonnese
authors.forename: L M
authors.initials: LM
authors.lastname: Fantozzi
authors.forename: A
authors.initials: A
authors.lastname: Bozzao
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000401:mortality*; D015331:Cohort Studies; D019175:DNA Methylation; D015254:DNA Modification Methylases / Q000235:genetics*; D045643:DNA Repair Enzymes / Q000235:genetics*; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D018572:Disease-Free Survival; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D005909:Glioblastoma / Q000175:diagnosis* / Q000235:genetics / Q000401:mortality* / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011379:Prognosis; D011401:Promoter Regions, Genetic; D016016:Proportional Hazards Models; D012372:ROC Curve; D012189:Retrospective Studies; D018570:Risk Assessment; D016019:Survival Analysis; D025521:Tumor Suppressor Proteins / Q000235:genetics*
chemical_list: D025521:Tumor Suppressor Proteins; D015254:DNA Modification Methylases; C515491:MGMT protein, human; D045643:DNA Repair Enzymes