title: Prostate volumetric assessment by magnetic resonance imaging and transrectal ultrasound: impact of variation in calculated prostate-specific antigen density on patient eligibility for active surveillance program.
abstract: OBJECTIVE
  The objective of this study was to investigate impact of prostate volume variations on prostate-specific antigen density (PSAD) and patient eligibility for active surveillance (AS).
  
  
  METHODS
  Prostate volume and PSAD were calculated for 46 patients with prostate cancer in AS who underwent prostate magnetic resonance imaging and transrectal ultrasound (TRUS). Manual method and 2 semiautomated methods for prostate segmentation (3D-SLICER and OsiriX) were used for MR volumetry.
  
  
  RESULTS
  Magnetic resonance volumetric methods showed very good agreement (intraclass correlation coefficient, 0.98). The concordance correlation coefficient was higher among MR volumetry methods (0.971-0.998) than between TRUS and MR volumetry (0.849-0.863). The variation in PSAD estimated by TRUS versus magnetic resonance imaging was higher in large prostates (r = 0.327, P = 0.027). Transrectal ultrasonography volumetry may improperly classify 20% of patients as eligible for AS with PSAD greater than 0.15 threshold.
  
  
  CONCLUSIONS
  Although clinically used TRUS reliably estimates PSAD, it may misclassify some patients who are not eligible for AS based on PSAD criteria. Magnetic resonance-based volumetry should be considered for a more reliable PSAD calculation.
authors.affiliation: The Russell H. Morgan Department of Radiology Radiological Science, The Johns Hopkins University, Baltimore, MD 21287, USA.
authors.forename: Seyed Saeid
authors.initials: SS
authors.lastname: Dianat
authors.forename: Ramiro M
authors.initials: RM
authors.lastname: Rancier Ruiz
authors.forename: David
authors.initials: D
authors.lastname: Bonekamp
authors.forename: H Ballentine
authors.initials: HB
authors.lastname: Carter
authors.forename: Katarzyna J
authors.initials: KJ
authors.lastname: Macura
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D018579:Patient Selection; D011159:Population Surveillance; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis*; D015203:Reproducibility of Results; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D014463:Ultrasonography / Q000379:methods*
chemical_list: D017430:Prostate-Specific Antigen