Augmented Reality PSMA-3D guided robotic pelvic lymph node dissection (PLND) in prostate cancer patients

Background and objective: Intraoperative identification of suspicious lymph node metastases (LNM) detected at PSMA-PET is key to achieve optimal surgical outcomes of robot-assisted radical prostatectomy (RARP) with pelvic lymph node dissection (PLND). We aim to describe a novel technique of augmented reality (AR)-PSMA-3D guided PLND based on preoperative PSMA-PET for real-time identification of LNM. Methods: Thirteen patients with high-risk PCa and miN1-2 or miM1a disease at PSMA-PET were prospectively enrolled. 3D segmentation model including suspicious LNM was created from PSMA-PET images. Intervention: Patients underwent RARP with AR-PSMA-3D guided PLND for real-time intraoperative identification of suspicious LNM. Pathologic examination was used as reference standard. Key findings and limitations: Four (30%) men had suspicious LNM at PSMA-PET outside the field of the PLND template. The AR-PSMA-3D guided PLND allow to dissect each region with suspected LNM at PSMA-PET with no intraoperative complications. Nine (69%) patients had pN1 disease and three (23%) men had nodal metastases outside the PLND template. The sensitivity, specificity, PPV, NPV and AUC of AR-PSMA-3D guided PLND at a per-region analysis were 69%, 90%, 52%, 95% and 0.79, respectively. Limitations: low spatial resolution of PSMA-PET for micro-metastases and the need for manual alignment of the 3D model. Conclusions and clinical implications: AR-PSMA-3D guidance for PLND in patients with miN1-N2-M1a disease at PSMA-PET allows to facilitate the resection of suspicious LNM including those outside the PLND template. We propose a novel technique combining AR and PSMA-PET 3D models to guide PLND during RARP in PCa patients. The AR-PSMA-3D guidance for PLND allows a promising real-time identification of suspicious nodes, even outside the PLND template.