MP66-10 IDENTIFYING CAPSULAR INVOLVEMENT DURING DISSECTION OF PERIPROSTATIC TISSUE USING 3D ELASTIC AUGMENTED-REALITY DURING ROBOT-ASSISTED RADICAL PROSTATECTOMY: A FEASIBILITY STUDY

Abstract

INTRODUCTION AND OBJECTIVES: During radical prostatectomy cancer abutting or focally extending beyond the prostate capsule increases the risk of a positive surgical margin. Thus, intraoperative knowledge of the three-dimensional (3D) location of cancer can help the surgeon reducing this risk. We specifically developed an Elastic Augmented-Reality (AR) system based on elastic Hyper-Accuracy 3D reconstruction (HA3DTM), that simulates prostate deformation during the procedure. The aim of this study is to evaluate the accuracy of this 3D Elastic AR system in identifying capsular involvement (CI) of PCa during the NS phase of robot-assisted radical prostatectomy (RARP). METHODS: We prospectively enrolled patients with prostate cancer (cT1-3, cN0, cM0) undergoing RARP from May to September 2018. Preoperative mp-MRI was performed and CI was revealed. The PCa diagnosis was based on a positive target biopsy at the index lesion. The images in DICOM format were processed by software authorized for medical use by MEDICS Srl, in order to perform the HA3DTM. A dedicated software was developed in order to allow the deformation of 3D virtual images simulating the prostate deformation exercised by robotic arms during the intervention. Among the non parametric deformation we selected bend and stretch as those most suited to our visualization and overlay purposes. 3D reconstruction obtained was integrated in the robotic console to perform AR-RARP. During the nerve-sparing phase a mark (a metallic clip) was placed at prostate capsule at the level of suspicious CI. RESULTS: 15 patients were enrolled. 16 lesions were identified at MRI. CI was confirmed at final pathology in 11 cases. At macroscopic evaluation the metallic clip was placed at the level of tumor and at level of suspicious capsule bulging in 16/16 (100%). Microscopic assessment was performed and confirmed cancer presence in 15/16 (93.7%) cases; moreover, CI was identified correctly in 11/11 (100.0%) cases. CONCLUSIONS: 15 patients were enrolled. 16 lesions were identified at MRI. CI was confirmed at final pathology in 11 cases. At macroscopic evaluation the metallic clip was placed at the level of tumor and at level of suspicious capsule bulging in 16/16 (100%). Microscopic assessment was performed and confirmed cancer presence in 15/16 (93.7%) cases; moreover, CI was identified correctly in 11/11 (100.0%) cases.