Modélisation Biomécanique pour l'Imagerie de Prostate (Biomechanical Modeling Applied to Prostate Imaging)

Abstract

In 2012 in France, prostate cancer was the most frequent cancer with 53 465 new cases estimated and 8 876 deaths. Transrectal prostate biopsy is the only method used to prove the presence of cancer with a histopathologic study. Twelve biopsies are evenly punctured all around the prostate by the urologist as well as targeted areas. This is generally done with the guidance of endorectal ultrasound images. The difficulties for the urologist are to perform this 3D task precisely and accurately based on 2D imaging. Moreover image acquisition itself contributes to prostate motion and deformation. It is within this framework that we proposed the development of patient-specific biomechanical model of prostate. This model can be used in a clinical time and is based only on 3D ultrasonographic volumes. The model allows the urologist to monitor the deformations and the displacements of the prostate and to follow targeted areas. Firstly, we were interested in building a validation workflow for prototyping and conducting a large-scale test to evaluate the impact of each necessary step before the dynamic simulation. An initial test was conducted with a realistic deformable prostate phantom. This experiment is based on more than 800 simulations allowing us to complete a statistical survey. We then developed and validated tools, such as the calibration of a robot probe-holder to improve the workflow and to perform real patient data acquisitions. An evaluation of the impact of each parameter of the biomechanical model was achieved on a realistic deformable prostate phantom. Finally, we had the opportunity to apply our workflow on one patient biopsy session acquisition. Results are encouraging and shows good perspectives to our work.