title: Incremental value of T2-weighted and diffusion-weighted MRI for prediction of biochemical recurrence after radical prostatectomy in clinically localized prostate cancer.
abstract: BACKGROUND
  For men with clinically localized prostate cancer and candidates to receive radical prostatectomy (RP) a main concern is a cancer recurrence after treatment. Although previous studies have demonstrated the diagnostic utility of diffusion-weighted imaging (DWI) for prostate cancer, the prognostic value of pretreatment DWI has not been investigated yet.
  
  
  OBJECTIVE
  To investigate the incremental value of MRI-based T staging using DWI and T2-weighted imaging (T2WI) as compared with the clinical parameters in prediction of biochemical recurrence (BCR) after RP for clinically localized prostate cancer.
  
  
  METHODS
  Sixty MR examinations, obtained before RP between April 2002 and March 2009, were retrospectively reviewed using T2WI alone, DWI alone, or T2WI + DWI for T staging according to the 2002 American Joint Committee on Cancer guidelines. The relationship between MRI stage and BCR was evaluated using Kaplan-Meier survival estimates. Multivariate analysis and receiver operating characteristics (ROC) curve analysis were used to investigate the incremental value over the standard clinical variables in prediction of BCR.
  
  
  RESULTS
  As of August 2009, 12 (20%) patients had BCR. Based on T2WI + DWI, both T3a (compared to OC disease) and T2 (compared to T1c) showed significantly higher BCR rates (p=0.047 and 0.025, respectively). Multivariate analysis and area under ROC curve analysis confirmed the additional value of MRI staging to the conventional clinical variables in prediction of BCR.
  
  
  CONCLUSIONS
  The combination of T2WI and DWI on performing pretreatment MRI helped predict BCR after RP in clinically localized prostate cancer.
authors.affiliation: Department of Radiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan. b97b36@koto.kpu-m.ac.jp
authors.forename: Kaori
authors.initials: K
authors.lastname: Nishida
authors.forename: Sachiko
authors.initials: S
authors.lastname: Yuen
authors.forename: Kazumi
authors.initials: K
authors.lastname: Kamoi
authors.forename: Kei
authors.initials: K
authors.lastname: Yamada
authors.forename: Kentaro
authors.initials: K
authors.lastname: Akazawa
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Ito
authors.forename: Koji
authors.initials: K
authors.lastname: Okihara
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kawauchi
authors.forename: Tsuneharu
authors.initials: T
authors.lastname: Miki
authors.forename: Tsunehiko
authors.initials: T
authors.lastname: Nishimura
mesh_terms: D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D006801:Humans; D053208:Kaplan-Meier Estimate; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D015588:Observer Variation; D011183:Postoperative Complications / Q000473:pathology*; D011237:Predictive Value of Tests; D011467:Prostate / Q000473:pathology / Q000601:surgery; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000601:surgery*; D012372:ROC Curve; D012189:Retrospective Studies