title: Likelihood of prostate cancer based on prostate-specific antigen density by MRI: retrospective analysis.
abstract: OBJECTIVE
  As a screening test for prostate cancer (PCA), prostate-specific antigen (PSA) may induce unnecessary prostate biopsy in patients with PSA 4.1-10.0 ng/ml. PCA detection may be delayed in patients with PSA < or =4.0 ng/ml. MRI-based PSA density of the prostate (PSAD) and of the prostatic transitional zone (PSAT) could improve differentiation of PCA and benign prostatic hyperplasia.
  
  
  METHODS
  Total prostate and transitional zone volumes were planimetrically determined in axial, T2-weighted fast spin echo MR images of the prostate. Serum PSA concentration was measured with an automated standardized microparticle enzyme immune assay. PSAD and PSAT were calculated in 17 patients with clinically significant PCA and 42 patients with benign prostatic hypertrophy (BPH) (66 +/- 6 versus 64 +/- 8 years, p = 0.2410, t test) who had PSA levels < or =10.0 ng/ml.
  
  
  RESULTS
  For differentiation of BPH and PCA, PSA alone above the optimal cutoff level of 4.2 ng/ml showed an odds ratio for PCA of 6.7 (95% confidence interval [CI], 1.9-23.2). PSAD showed an odds ratio for PCA of 71.3 (95% CI, 11.8-430.9) above the optimal cutoff level of 0.07 ng/ml/cc. PSAT demonstrated an odds ratio for PCA of 320.0 (95% CI, 27.1-3781.4) above the optimal cutoff level of 0.15 ng/ml/cc.
  
  
  CONCLUSIONS
  In patients with PSA < or =10.0 ng/ml, MRI-based PSAD and PSAT appear to improve differentiation of prostate cancer and BPH and are feasible to reduce the frequency of unnecessary prostate biopsy.
authors.affiliation: Department of Radiology, Klinikum Grosshadern, University of Munich, Germany. m-lisse@ikra.med.uni-muenchen.de
authors.forename: Ullrich G
authors.initials: UG
authors.lastname: Mueller-Lisse
authors.forename: Ulrike L
authors.initials: UL
authors.lastname: Mueller-Lisse
authors.forename: Steffen
authors.initials: S
authors.lastname: Haller
authors.forename: Peter
authors.initials: P
authors.lastname: Schneede
authors.forename: Juergen E
authors.initials: JE
authors.lastname: Scheidler
authors.forename: Nicolaus
authors.initials: N
authors.lastname: Schmeller
authors.forename: Alfons G
authors.initials: AG
authors.lastname: Hofstetter
authors.forename: Maximilian F
authors.initials: MF
authors.lastname: Reiser
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D001706:Biopsy; D003937:Diagnosis, Differential; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D011467:Prostate / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood*; D011470:Prostatic Hyperplasia / Q000175:diagnosis; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D012189:Retrospective Studies; D012984:Software
chemical_list: D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen