Tractography-Guided Nerve-Sparing in Prostate Cancer

Description

Radical prostatectomy (RP) is an effective treatment leading to a high rate of oncological control. However, despite advances in robot-assisted RP, the genito-urinary function, especially erectile function and urinary continence, may be significantly impaired after surgery. Our study aims to characterize and map the nerve fibers surrounding the prostate before and after surgery using diffusion tensor magnetic resonance imaging (DTI), a non-invasive magnetic resonance imaging (MRI) technique. This relatively new technology, combined with the 3D tractography software, will allow us to create a personalized 3D model of the periprostatic nerves. This virtual model will help us to assess the nerve bundles and how the surgery impacts their integrity. DTI and 3D reconstruction will be performed before and 6 months after surgery. The pre-surgery 3D virtual model will be overlaid and mapped onto the intraoperative surgical view, providing the surgeon with a visual guide of the nerve fiber organization. At the post-surgery level, the 3D virtual model of the nerve bundles will be compared to the pre-surgery model. Post-treatment changes at 6 months may help assess nerve preservation and their relationship with erectile (dys)function. The main questions the clinical study aims to answer are: 1. Post-treatment DTI-Tractography parameter changes at 6 months may help assess nerve recovery and their relationship with erectile (dys)function (PROMs - IIEF-5 score) 2. Post-treatment DTI-Tractography parameter changes at 6 months may help assess their relationship with urinary function 3. At the post-surgery level, the 3D virtual model of the nerve bundles will be compared to the pre-surgery 3D model. 4. The pre-surgery 3D virtual model will be overlaid and mapped onto the intraoperative surgical view, providing the surgeon with a visual guide of the nerve fiber organization (mean surgery time, surgeon feedback assessment, etc., will be evaluated.) Tumor location based on the 3D model will also be explored.

Interventions

• Prostate Tractography for Nerve-Sparing (Procedure)
  Tractography will be performed according to established best practices. To create the 3DVM, a high-performance workstation equipped with a high-end GPU will be used. ROI placement for nerve tractography and segmentation tasks will be performed semi-automatically using a previously trained nnU-Net pipeline. All inference will be strictly performed locally on this dedicated machine resulting in 4 segment masks (Prostate, Urethra, Index Lesion, Seminal Vesicles) that will be manually reviewed and corrected. The subsequent reconstructed Tractography bundles will be added to create the 3DTVM. The 3DTV model will be overlaid and mapped onto the intraoperative surgical view, providing the surgeon with a visual guide of the nerve fiber organizations (mean surgery time, surgeon feedback etc will be evaluated.)

Eligibility criteria

Conditions

Locations

• Hôpitaux Universitaires de Genève - Dept de Chirurgie - Service d'Urologie — Geneva, Canton of Geneva, Switzerland