title: Accuracy of preoperative endorectal MRI in predicting extracapsular extension and influence on neurovascular bundle sparing in radical prostatectomy.
abstract: OBJECTIVE
  To evaluate the accuracy of presurgical endorectal MRI (eMRI) for local staging before radical prostatectomy (RP) and its influence on neurovascular bundle (NVB) resection during radical prostatectomy.
  
  
  METHODS
  A total of 385 patients with histologically proven prostate cancer (PCa) have been included in this retrospective study between 2004 and 2008. All patients underwent preoperative eMRI at 1.5 T before open RP. Staging results by eMRI were compared with the histopathological findings. The presence of positive surgical margins and extent of nerve-sparing procedure were evaluated. Subgroup analysis of low-risk group and intermediate to high-risk group based on D'Amico criteria was conducted.
  
  
  RESULTS
  In 294 (76.4%) patients, pathological stage was correctly predicted, 69 patients (17.9%) were understaged and 22 (5.7%) overstaged. Overall sensitivity, specificity, negative and positive predictive value for predicting extracapsular extension (ECE) were 41.5, 91.8, 78.0 and 69.0%, respectively. One hundred and fifty-two (48.4%) of the patients classified as stage cT2 by eMRI underwent bilateral NVB sparing, whereas 14 (19.7%) patients with reported ECE underwent bilateral NVB sparing (P < 0.01). Overall positive surgical margin rate was 14.8%. Sensitivity of predicting ECE and positive predictive value were lower in the low-risk group than in the intermediate and high-risk group.
  
  
  CONCLUSIONS
  eMRI is effective in predicting extracapsular extension in an intermediate to high-risk group. Preoperative eMRI in patients with low-risk criteria is not recommended as a routine assessment modality. eMRI findings did appear to influence surgical strategy as patients with imaging findings suggesting >cT2 disease were less likely to undergo NVB sparing.
authors.affiliation: Department of Radiology, Comprehensive Cancer Center (CCC) Tübingen, Eberhard-Karls-Universität Tübingen, Tübingen, Germany.
authors.forename: Matthias C
authors.initials: MC
authors.lastname: Roethke
authors.forename: Matthias P
authors.initials: MP
authors.lastname: Lichy
authors.forename: Michaela
authors.initials: M
authors.lastname: Kniess
authors.forename: Matthias K
authors.initials: MK
authors.lastname: Werner
authors.forename: Claus D
authors.initials: CD
authors.lastname: Claussen
authors.forename: Arnulf
authors.initials: A
authors.lastname: Stenzl
authors.forename: Heinz-Peter
authors.initials: HP
authors.lastname: Schlemmer
authors.forename: David
authors.initials: D
authors.lastname: Schilling
mesh_terms: D000328:Adult; D000368:Aged; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D059351:Organ Sparing Treatments / Q000379:methods*; D018579:Patient Selection; D011237:Predictive Value of Tests; D011300:Preoperative Care; D011467:Prostate / Q000294:innervation* / Q000473:pathology / Q000601:surgery; D011468:Prostatectomy / Q000379:methods*; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000601:surgery*; D012007:Rectum; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity