  : Introduction-objectives: A virtual-reality learning environment dedicated
to prostate biopsies was designed to overcome the limitations of current
classical teaching methods. The aim of this study was to validate reliability,
face, content and construct of the simulator. Materials and methods: The
simulator is composed of a) a laptop computer, b) a haptic device with a stylus
that mimics the ultrasound probe, c) a clinical case database including three
dimensional (3D) ultrasound volumes and patient data and d) a learning
environment with a set of progressive exercises including a randomized 12-core
biopsy procedure. Both visual (3D biopsy mapping) and numerical (score)
feedback are given to the user. The simulator evaluation was conducted in an
academic urology department on 7 experts and 14 novices who each performed a
virtual biopsy procedure and completed a face and content validity
questionnaire. Results: The overall realism of the biopsy procedure was rated
at a median of 9/10 by non-experts (7.1-9.8). Experts rated the usefulness of
the simulator for the initial training of urologists at 8.2/10 (7.9-8.3), but
reported the range of motion and force feedback as significantly less realistic
than novices (p=0.01 and 0.03 respectively). Pearson's r correlation
coefficient between correctly placed biopsies on the right and left side of the
prostate for each user was 0.79 (p<0.001). The 7 experts had a median score of
64% (59-73), and the 14 novices a median score of 52% (43-67), without reaching
statistical significance (p=0,19). Conclusion: The newly designed virtual
reality learning environment proved its versatility and its reliability, face
and content were validated. Demonstrating the construct validity will require
improvements to the realism and scoring system used.
