title: Routine pelvic MRI using phased-array coil for detection of extraprostatic tumour extension: accuracy and clinical significance.
abstract: OBJECTIVE
  To determine the accuracy and assess the clinical significance of surface-coil 1.5-T magnetic resonance imaging (MRI) for the detection of locally advanced prostate cancer (PCa).
  
  
  METHODS
  Between December 2007 and January 2010, we examined 209 PCa patients (mean age = 62.5 years) who were consecutively treated with robot-assisted laparoscopic prostatectomy and prospectively staged by MRI. One hundred and thirty-five patients (64.6 %) had locally advanced disease. Conventional clinical tumour stage and MRI-assessed tumour stage were compared with histopathological tumour stage (pT). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and overall accuracy (OA) were calculated using pT as the "gold standard". Overstaged and understaged cases at MRI were reviewed.
  
  
  RESULTS
  Sensitivity, specificity, PPV, NPV and OA for the detection of locally advanced disease were 25.9, 95.9, 92.1, 41.2 and 50.5 % and 56.3, 82.2, 85.4, 50.4 and 65.4 % for clinical staging and MRI, respectively. Among patients understaged at MRI, the resection margins were free in 64.4 % of the cases (38/59).
  
  
  CONCLUSIONS
  Although the accuracy was limited, the detection of locally advanced disease improved substantially when MRI was added to routine clinical staging. The majority of the understaged patients nevertheless achieved free margins. When assessing the clinical significance of MRI staging the extent of extraprostatic extension has to be considered.
authors.affiliation: Department of Radiology and Nuclear Medicine, Radiumhospitalet, Oslo University Hospital, Montebello, 0310 Oslo, Norway.
authors.forename: Knut Håkon
authors.initials: KH
authors.lastname: Hole
authors.forename: Karol
authors.initials: K
authors.lastname: Axcrona
authors.forename: Agnes Kathrine
authors.initials: AK
authors.lastname: Lie
authors.forename: Ljiljana
authors.initials: L
authors.lastname: Vlatkovic
authors.forename: Oliver Marcel
authors.initials: OM
authors.lastname: Geier
authors.forename: Bjørn
authors.initials: B
authors.lastname: Brennhovd
authors.forename: Kjetil
authors.initials: K
authors.lastname: Knutstad
authors.forename: Dag Rune
authors.initials: DR
authors.lastname: Olsen
authors.forename: Therese
authors.initials: T
authors.lastname: Seierstad
mesh_terms: D000328:Adult; D000368:Aged; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D010388:Pelvis / Q000473:pathology*; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000601:surgery*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome