title: The role of preoperative endorectal magnetic resonance imaging in the decision regarding whether to preserve or resect neurovascular bundles during radical retropubic prostatectomy.
abstract: BACKGROUND
  Because the recovery of erectile function and the avoidance of positive surgical margins are important but competing outcomes, the decision to preserve or resect a neurovascular bundle (NVB) during radical prostatectomy (RP) should be based on the most accurate information concerning the location and extent of the tumor. In the current study, the authors determined the incremental value of endorectal magnetic resonance imaging (eMRI) in making this decision.
  
  
  METHODS
  eMRI was performed in 135 patients preoperatively. For each NVB, tumor extension to the NVB and the need for NVB resection was judged by a surgeon on a scale from 1 (definite preservation) to 5 (definite resection) before and after reviewing eMRI with a radiologist. Histopathologic findings were used as the standard of reference. The value of eMRI was assessed using binormal receiver operating characteristic (ROC) analysis adjusted for multiple observations per patient, and a mixed effects ordinal regression model was used for risk stratification.
  
  
  RESULTS
  Histopathologic examination determined that NVB resection was warranted in 44 of 270 NVBs (16%) because of posterolateral extracapsular extension (n = 29), positive surgical margins (n = 7), or both (n = 8). The areas under the ROC curves (AUC) were 0.741 for pre-MRI and 0.832 for post-MRI surgical planning (P < 0.01). MRI findings suggested altering the surgical plan in 39% of NVBs (106 of 270 NVBs). When the surgeon judged that the NVB resection was definitely not necessary (165 NVBs), MRI confirmed that decision in 138 NVBs (84%); the concordant decision was correct in 96% of the cases (133 of 138 NVBs). In 36 high-risk patients (> or = 75% probability of extracapsular extension), MRI findings changed the surgical plan for 28 NVBs (78%); the change was found to be appropriate in 26 cases (93%).
  
  
  CONCLUSIONS
  MRI was found to significantly improve the surgeon's decision to preserve or resect the NVB during radical prostatectomy.
authors.affiliation: Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA. Hricakh@mskcc.org
authors.forename: Hedvig
authors.initials: H
authors.lastname: Hricak
authors.forename: Liang
authors.initials: L
authors.lastname: Wang
authors.forename: David C
authors.initials: DC
authors.lastname: Wei
authors.forename: Fergus V
authors.initials: FV
authors.lastname: Coakley
authors.forename: Oguz
authors.initials: O
authors.lastname: Akin
authors.forename: Victor E
authors.initials: VE
authors.lastname: Reuter
authors.forename: Mithat
authors.initials: M
authors.lastname: Gonen
authors.forename: Michael W
authors.initials: MW
authors.lastname: Kattan
authors.forename: Chinyere N
authors.initials: CN
authors.lastname: Onyebuchi
authors.forename: Peter T
authors.initials: PT
authors.lastname: Scardino
mesh_terms: D000328:Adult; D000368:Aged; D005189:False Positive Reactions; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011300:Preoperative Care; D011468:Prostatectomy / Q000379:methods*; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery*; D012007:Rectum / Q000098:blood supply* / Q000294:innervation*