  Prostate biopsies are mainly performed under 2D TransRectal UltraSound (TRUS)
control by sampling the prostate according to a predefined pattern. In case of
first biopsies, this pattern follows a random systematic plan. Sometimes,
repeat biopsies can be needed to target regions unsampled by previous biopsies
or resample critical regions (for example in case of cancer expectant
management or previous prostatic intraepithelial neoplasia findings). From a
clinical point of view, it could be useful to control the 3D spatial
distribution of theses biopsies inside the prostate. Modern 3D-TRUS probes
allow acquiring high-quality volumes of the prostate in few seconds. We
developed a framework to track the prostate in 3D TRUS images. It means that if
one acquires a reference volume at the beginning of the session and another
during each biopsy, it is possible to determine the relationship between the
prostate in the reference and the others volumes by aligning images. We used
this tool to evaluate the ability of a single operator (a young urologist
assistant professor) to perform a pattern of 12 biopsies under 2D TRUS
guidance.
