title: Serial Magnetic Resonance Imaging in Active Surveillance of Prostate Cancer: Incremental Value.
abstract: OBJECTIVE
  We assessed whether changes in serial multiparametric magnetic resonance imaging can help predict the pathological progression of prostate cancer in men on active surveillance.
  
  
  METHODS
  A retrospective cohort study was conducted of 49 consecutive men with Gleason 6 prostate cancer who underwent multiparametric magnetic resonance imaging at baseline and again more than 6 months later, each followed by a targeted prostate biopsy, between January 2011 and May 2015. We evaluated whether progression on multiparametric magnetic resonance imaging (an increase in index lesion suspicion score, increase in index lesion volume or decrease in index lesion apparent diffusion coefficient) could predict pathological progression (Gleason 3 + 4 or greater on subsequent biopsy, in systematic or targeted cores). Diagnostic performance of multiparametric magnetic resonance imaging was determined with and without clinical data using a binary logistic regression model.
  
  
  RESULTS
  The mean interval between baseline and followup multiparametric magnetic resonance imaging was 28.3 months (range 11 to 43). Pathological progression occurred in 19 patients (39%). The sensitivity, specificity, positive predictive value and negative predictive value of multiparametric magnetic resonance imaging was 37%, 90%, 69% and 70%, respectively. Area under the receiver operating characteristic curve was 0.63. A logistic regression model using clinical information (maximum cancer core length greater than 3 mm on baseline biopsy or a prostate specific antigen density greater than 0.15 ng/ml(2) at followup biopsy) had an AUC of 0.87 for predicting pathological progression. The addition of serial multiparametric magnetic resonance imaging data significantly improved the AUC to 0.91 (p=0.044).
  
  
  CONCLUSIONS
  Serial multiparametric magnetic resonance imaging adds incremental value to prostate specific antigen density and baseline cancer core length for predicting Gleason 6 upgrading in men on active surveillance.
authors.affiliation: Department of Radiology, Ronald Reagan-UCLA Medical Center, Los Angeles, California.
authors.forename: Ely R
authors.initials: ER
authors.lastname: Felker
authors.affiliation: Department of Urology, David Geffen School of Medicine, Los Angeles, California.
authors.forename: Jason
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Urology, David Geffen School of Medicine, Los Angeles, California; Department of Bioengineering, University of California Los Angeles, Los Angeles, California.
authors.forename: Shyam
authors.initials: S
authors.lastname: Natarajan
authors.affiliation: Department of Radiology, Ronald Reagan-UCLA Medical Center, Los Angeles, California.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Margolis
authors.affiliation: Department of Radiology, Ronald Reagan-UCLA Medical Center, Los Angeles, California.
authors.forename: Steven S
authors.initials: SS
authors.lastname: Raman
authors.affiliation: Department of Pathology, David Geffen School of Medicine, Los Angeles, California.
authors.forename: Jiaoti
authors.initials: J
authors.lastname: Huang
authors.affiliation: Department of Urology, David Geffen School of Medicine, Los Angeles, California.
authors.forename: Fred
authors.initials: F
authors.lastname: Dorey
authors.affiliation: Department of Urology, David Geffen School of Medicine, Los Angeles, California. Electronic address: lmarks@mednet.ucla.edu.
authors.forename: Leonard S
authors.initials: LS
authors.lastname: Marks
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002140:California / Q000453:epidemiology; D018450:Disease Progression; D005500:Follow-Up Studies; D006801:Humans; D061705:Image-Guided Biopsy / Q000379:methods*; D015994:Incidence; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D012372:ROC Curve; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D018426:SEER Program; D013997:Time Factors; D057832:Watchful Waiting
keywords: magnetic resonance imaging; prostatic neoplasms; watchful waiting