title: Repeat prostate biopsy accuracy: simulator-based comparison of two- and three-dimensional transrectal US modalities.
abstract: OBJECTIVE
  To compare the accuracy of biopsy with two-dimensional (2D) transrectal ultrasonography (US) with that of biopsy with conventional three-dimensional (3D) transrectal US and biopsy with guided 3D transrectal US in the guidance of repeat prostate biopsy procedures in a prostate biopsy simulator.
  
  
  METHODS
  The institutional review board approved this retrospective study. Five residents and five experts performed repeat biopsies with a biopsy simulator that contained the transrectal US prostate images of 10 patients who had undergone biopsy. Simulated repeat biopsies were performed with 2D transrectal US, conventional 3D transrectal US, and guided 3D transrectal US (an extension of 3D transrectal US that enables active display of biopsy targets). The modalities were compared on the basis of time per biopsy and how accurately simulated repeat biopsies could be guided to specific targets. The probability for successful biopsy of a repeat target was calculated for each modality.
  
  
  RESULTS
  Guided 3D transrectal US was significantly (P < .01) more accurate for simulated biopsy of repeat targets than was 2D or 3D transrectal US, with a biopsy accuracy of 0.86 mm +/- 0.47 (standard deviation), 3.68 mm +/- 2.60, and 3.60 mm +/- 2.57, respectively. Experts had a 70% probability of sampling a prior biopsy target volume of 0.5 cm(3) with 2D transrectal US; however, the probability approached 100% with guided 3D transrectal US. Biopsy accuracy was not significantly different between experts and residents for any modality; however, experts were significantly (P < .05) faster than residents with each modality.
  
  
  CONCLUSIONS
  Repeat biopsy of the prostate with 2D transrectal US has limited accuracy. Compared with 2D transrectal US, the biopsy accuracy of both experts and residents improved with guided 3D transrectal US but did not improve with conventional 3D transrectal US.
authors.affiliation: Imaging Research Laboratories, Robarts Research Institute, University of Western Ontario, London, Canada. dcool2011@meds.uwo.ca
authors.forename: Derek W
authors.initials: DW
authors.lastname: Cool
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Connolly
authors.forename: Shi
authors.initials: S
authors.lastname: Sherebrin
authors.forename: Roy
authors.initials: R
authors.lastname: Eagleson
authors.forename: Jonathan I
authors.initials: JI
authors.lastname: Izawa
authors.forename: Justin
authors.initials: J
authors.lastname: Amann
authors.forename: Cesare
authors.initials: C
authors.lastname: Romagnoli
authors.forename: Walter M
authors.initials: WM
authors.lastname: Romano
authors.forename: Aaron
authors.initials: A
authors.lastname: Fenster
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000473:pathology*; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D001706:Biopsy; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D019047:Phantoms, Imaging; D011467:Prostate / Q000000981:diagnostic imaging / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D012007:Rectum / Q000000981:diagnostic imaging*; D019233:Retreatment; D012189:Retrospective Studies; D014463:Ultrasonography / Q000379:methods*