title: Evaluation of the prostate imaging reporting and data system for the detection of prostate cancer by the results of targeted biopsy of the prostate.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the magnetic resonance prostate imaging reporting and data system (PI-RADS) for the detection of prostate cancer by the results of magnetic resonance imaging (MRI)-guided biopsy of the prostate as a reference standard.
  
  
  METHODS
  In 55 patients who had undergone MRI-guided biopsy of the prostate, we retrospectively matched every biopsy core with the corresponding lesion in previously acquired endorectal multiparametric MRI including T2-weighted imaging (T2WI), diffusion-weighted imaging (DWI), and dynamic contrast-enhanced MRI (DCE-MRI) at 1.5 T. Two readers blinded to the results of the biopsy evaluated each biopsied lesion according to the PI-RADS scoring system. The results of the targeted biopsy were used as a reference standard. Receiver operating characteristic analysis was performed for statistical analysis.
  
  
  RESULTS
  A total of 113 lesions in the 55 patients were evaluated; 30 lesions were malignant. When evaluated according to the criteria of the PI-RADS scoring system, DCE-MRI revealed a lower area under the receiver operating characteristic curve (AUC) (0.76) compared with T2WI (0.88; P=0.06) and DWI (0.93; P=0.004). A sum score combining T2WI, DWI, and DCE-MRI yielded an AUC of 0.93, whereas a sum score combining only T2WI and DWI yielded an AUC of 0.95. In central gland lesions, T2WI showed a numerically higher AUC compared with DWI (0.98 and 0.95), whereas, in peripheral zone lesions, DWI was superior (AUC of 0.93 and 0.73; P=0.04). An approach assigning a PI-RADS score for T2WI to central gland lesions and for DWI to peripheral zone lesions yielded an AUC of 0.96 and was numerically superior compared with any sequence alone and sum scores combining T2WI and DWI as well as T2WI, DWI, and DCE-MRI.
  
  
  CONCLUSIONS
  The PI-RADS scoring system shows a good diagnostic performance for the detection of prostate cancer when using a sum score. However, DCE-MRI does not seem to add significant value when evaluated according to the recommended criteria. Assigning a score for T2WI to central gland lesions and for DWI to peripheral zone lesions might be sufficient for stratification of patients for further diagnostic workup.
authors.affiliation: From the *Institut für Radiologie, †Klinik für Urologie, Charité - Universitätsmedizin Berlin, Campus Charité Mitte, Berlin; ‡Zentrum für Radiologie, Universitätsklinikum Jena, Jena; §Institut für Pathologie, Charité - Universitätsmedizin Berlin, Campus Charité Mitte; ∥Imaging Science Institute, Charité Berlin; and ¶SCO:SSiS Statistical Consulting, Berlin, Germany.
authors.forename: Alexander D J
authors.initials: AD
authors.lastname: Baur
authors.forename: Andreas
authors.initials: A
authors.lastname: Maxeiner
authors.forename: Tobias
authors.initials: T
authors.lastname: Franiel
authors.forename: Ergin
authors.initials: E
authors.lastname: Kilic
authors.forename: Alexander
authors.initials: A
authors.lastname: Huppertz
authors.forename: Carsten
authors.initials: C
authors.lastname: Schwenke
authors.forename: Bernd
authors.initials: B
authors.lastname: Hamm
authors.forename: Tahir
authors.initials: T
authors.lastname: Durmus
mesh_terms: D000368:Aged; D001706:Biopsy / Q000379:methods*; D003937:Diagnosis, Differential; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods; D053783:Magnetic Resonance Imaging, Interventional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011471:Prostatic Neoplasms / Q000175:diagnosis*; D019233:Retreatment; D012189:Retrospective Studies; D012680:Sensitivity and Specificity