title: Mapping of transrectal ultrasonographic prostate biopsies: quality control and learning curve assessment by image processing.
abstract: OBJECTIVE
  Mapping of transrectal ultrasonographic (TRUS) prostate biopsies is of fundamental importance for either diagnostic purposes or the management and treatment of prostate cancer, but the localization of the cores seems inaccurate. Our objective was to evaluate the capacities of an operator to plan transrectal prostate biopsies under 2-dimensional TRUS guidance using a registration algorithm to represent the localization of biopsies in a reference 3-dimensional ultrasonographic volume.
  
  
  METHODS
  Thirty-two patients underwent a series of 12 prostate biopsies under local anesthesia performed by 1 operator using a TRUS probe combined with specific third-party software to verify that the biopsies were indeed conducted within the planned targets.
  
  
  RESULTS
  The operator reached 71% of the planned targets with substantial variability that depended on their localization (100% success rate for targets in the middle and right parasagittal parts versus 53% for targets in the left lateral base). Feedback from this system after each series of biopsies enabled the operator to significantly improve his dexterity over the course of time (first 16 patients: median score, 7 of 10 and cumulated median biopsy length in targets of 90 mm; last 16 patients, median score, 9 of 10 and a cumulated median length of 121 mm; P = .046).
  
  
  CONCLUSIONS
  In addition to being a useful tool to improve the distribution of prostate biopsies, the potential of this system is above all the preparation of a detailed "map" of each patient showing biopsy zones without substantial changes in routine clinical practices.
authors.affiliation: Department of Urology, Assistance Publique-Hôpitaux de Paris, Paris, France. pierre.mozer@psl.aphp.fr
authors.forename: Pierre
authors.initials: P
authors.lastname: Mozer
authors.forename: Michael
authors.initials: M
authors.lastname: Baumann
authors.forename: Gregoire
authors.initials: G
authors.lastname: Chevreau
authors.forename: Alexandre
authors.initials: A
authors.lastname: Moreau-Gaudry
authors.forename: Stephane
authors.initials: S
authors.lastname: Bart
authors.forename: Raphaele
authors.initials: R
authors.lastname: Renard-Penna
authors.forename: Eva
authors.initials: E
authors.lastname: Comperat
authors.forename: Pierre
authors.initials: P
authors.lastname: Conort
authors.forename: Marc-Olivier
authors.initials: MO
authors.lastname: Bitker
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Chartier-Kastler
authors.forename: Francois
authors.initials: F
authors.lastname: Richard
authors.forename: Jocelyne
authors.initials: J
authors.lastname: Troccaz