[Real-time three-dimensional (4D) ultrasound-guided prostatic biopsies on a phantom. Comparative study versus 2D guidance].

OBJECTIVE

The objective of this study was to determine the added value of real-time three-dimensional (4D) ultrasound guidance of prostatic biopsies on a prostate phantom in terms of the precision of guidance and distribution.

METHODS

A prostate phantom was constructed. A real-time 3D ultrasonograph connected to a transrectal 5.9 MHz volumic transducer was used. Fourteen operators performed 336 biopsies with 2D guidance then 4D guidance according to a 12-biopsy protocol. Biopsy tracts were modelled by segmentation in a 3D ultrasound volume. Specific software allowed visualization of biopsy tracts in the reference prostate and evaluated the zone biopsied. A comparative study was performed to determine the added value of 4D guidance compared to 2D guidance by evaluating the precision of entry points and target points. The distribution was evaluated by measuring the volume investigated and by a redundancy ratio of the biopsy points.

RESULTS

The precision of the biopsy protocol was significantly improved by 4D guidance (p = 0.037). No increase of the biopsy volume and no improvement of the distribution of biopsies were observed with 4D compared to 2D guidance.

CONCLUSION

The real-time 3D ultrasound-guided prostate biopsy technique on a phantom model appears to improve the precision and reproducibility of a biopsy protocol, but the distribution of biopsies does not appear to be improved.