title: Dynamic contrast-enhanced ultrasound parametric imaging for the detection of prostate cancer.
abstract: OBJECTIVE
  To investigate the value of dynamic contrast-enhanced (DCE)-ultrasonography (US) and software-generated parametric maps in predicting biopsy outcome and their potential to reduce the amount of negative biopsy cores.
  
  
  METHODS
  For 651 prostate biopsy locations (82 consecutive patients) we correlated the interpretation of DCE-US recordings with and without parametric maps with biopsy results. The parametric maps were generated by software which extracts perfusion parameters that differentiate benign from malignant tissue from DCE-US recordings. We performed a stringent analysis (all tumours) and a clinical analysis (clinically significant tumours). We calculated the potential reduction in biopsies (benign on imaging) and the resultant missed positive biopsies (false-negatives). Additionally, we evaluated the performance in terms of sensitivity, specificity negative predictive value (NPV) and positive predictive value (PPV) on a per-prostate level.
  
  
  RESULTS
  Based on DCE-US, 470/651 (72.2%) of biopsy locations appeared benign, resulting in 40 false-negatives (8.5%), considering clinically significant tumours only. Including parametric maps, 411/651 (63.1%) of the biopsy locations appeared benign, resulting in 23 false-negatives (5.6%). In the per-prostate clinical analysis, DCE-US classified 38/82 prostates as benign, missing eight diagnoses. Including parametric maps, 31/82 prostates appeared benign, missing three diagnoses. Sensitivity, specificity, PPV and NPV were 73, 58, 50 and 79%, respectively, for DCE-US alone and 91, 56, 57 and 90%, respectively, with parametric maps.
  
  
  CONCLUSIONS
  The interpretation of DCE-US with parametric maps allows good prediction of biopsy outcome. A two-thirds reduction in biopsy cores seems feasible with only a modest decrease in cancer diagnosis.
authors.affiliation: Department of Urology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Arnoud W
authors.initials: AW
authors.lastname: Postema
authors.affiliation: Bracco Suisse SA, Geneva, Switzerland.
authors.forename: Peter J A
authors.initials: PJ
authors.lastname: Frinking
authors.affiliation: Department of Urology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Martijn
authors.initials: M
authors.lastname: Smeenge
authors.affiliation: Department of Urology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Theo M
authors.initials: TM
authors.lastname: De Reijke
authors.affiliation: Department of Urology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Jean J M C H
authors.initials: JJ
authors.lastname: De la Rosette
authors.affiliation: Bracco Suisse SA, Geneva, Switzerland.
authors.forename: Francois
authors.initials: F
authors.lastname: Tranquart
authors.affiliation: Department of Urology, Academic Medical Center, Amsterdam, The Netherlands.
authors.forename: Hessel
authors.initials: H
authors.lastname: Wijkstra
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D062005:Biopsy, Large-Core Needle; D055088:Early Detection of Cancer; D005240:Feasibility Studies; D006801:Humans; D061705:Image-Guided Biopsy; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011467:Prostate / Q000000981:diagnostic imaging / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D012680:Sensitivity and Specificity; D047368:Tumor Burden; D014463:Ultrasonography
keywords: contrast-enhanced ultrasound; parametric imaging; prostate cancer imaging; quantification