title: Performance of multiparametric MRI in men at risk of prostate cancer before the first biopsy: a paired validating cohort study using template prostate mapping biopsies as the reference standard.
abstract: BACKGROUND
  Multiparametric magnetic resonance imaging (mpMRI) has the potential to serve as a non-invasive triage test for men at risk of prostate cancer. Our objective was to determine the performance characteristics of mpMRI in men at risk before the first biopsy using 5 mm template prostate mapping (TPM) as the reference standard.
  
  
  METHODS
  One hundred and twenty-nine consecutive men with clinical suspicion of prostate cancer, who had no prior biopsy, underwent mpMRI (T1/T2-weighted, diffusion-weighting, dynamic contrast enhancement) followed by TPM. The primary analysis used were as follows: (a) radiological scores of suspicion of ≥3 attributed from a five-point ordinal scale, (b) a target condition on TPM of any Gleason pattern ≥4 and/or a maximum cancer core length of ≥4 mm and (c) two sectors of analysis per prostate (right and left prostate halves). Secondary analyses evaluated the impact of changing the mpMRI score threshold to ≥4 and varying the target definition for clinical significance.
  
  
  RESULTS
  One hundred and forty-one out of 258 (55%) sectors of analysis showed 'any cancer' and 77/258 (30%) had the target histological condition for the purpose of deriving the primary outcome. Median (with range) for age, PSA, gland volume and number of biopsies taken were 62 years (41-82), 5.8 ng ml(-1) (1.2-20), 40 ml (16-137) and 41 cores (20-93), respectively. For the primary outcome sensitivity, specificity, positive and negative predictive values and area under the receiver-operating curve (with 95% confidence intervals) were 94% (88-99%), 23% (17-29%), 34% (28-40%), 89% (79-98%) and 0.72 (0.65-0.79), respectively.
  
  
  CONCLUSIONS
  MpMRI demonstrated encouraging diagnostic performance characteristics in detecting and ruling out clinically significant prostate cancer in men at risk, who were biopsy naive.
authors.affiliation: 1] Department of Urology, University College London Hospitals NHS Foundation Trust, London, UK [2] Department of Urology, Faculty of Medicine, Fayoum University, Fayoum, Egypt.
authors.forename: M
authors.initials: M
authors.lastname: Abd-Alazeez
authors.affiliation: Department of Radiology, University College London Hospitals NHS Foundation Trust, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Kirkham
authors.affiliation: 1] Department of Urology, University College London Hospitals NHS Foundation Trust, London, UK [2] Division of Surgery and Interventional Science, University College London, London, UK.
authors.forename: H U
authors.initials: HU
authors.lastname: Ahmed
authors.affiliation: 1] Department of Urology, University College London Hospitals NHS Foundation Trust, London, UK [2] Barts Cancer Institute, Queen Mary, University of London, London, UK.
authors.forename: M
authors.initials: M
authors.lastname: Arya
authors.affiliation: Clinical Effectiveness Unit, Royal College of Surgeons of England, London, UK.
authors.forename: E
authors.initials: E
authors.lastname: Anastasiadis
authors.affiliation: Department of Health Services Research and Policy, London School of Hygiene and Tropical Medicine, University of London, London, UK.
authors.forename: S C
authors.initials: SC
authors.lastname: Charman
authors.affiliation: Department of Histopathology, University College London Hospitals NHS Foundation Trust, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Freeman
authors.affiliation: 1] Department of Urology, University College London Hospitals NHS Foundation Trust, London, UK [2] Division of Surgery and Interventional Science, University College London, London, UK.
authors.forename: M
authors.initials: M
authors.lastname: Emberton
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D015331:Cohort Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009929:Organ Size; D017063:Outcome Assessment, Health Care; D011467:Prostate / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D017430:Prostate-Specific Antigen