Precise and minimally invasive localization of pelvic nodes during robot-assisted surgery using image-guided navigation

Purpose: Image-guided surgical navigation can enhance surgical precision and safety. The rise of robot-assisted surgeries has increased the need of incorporating navigation systems. Our goal is to evaluate the integration of three novel techniques on registration, instrument tracking and visualization with navigation using the robot-assisted sentinel lymph node biopsy (SLNB).

Methods: A prospective feasibility study was performed at the Netherlands Cancer Institute (November 2023–July 2025). In total, 30 patients scheduled for SLNB participated. First, registration and localization accuracy were analyzed. Secondly, surgeons answered questionnaires to evaluate the ultrasound registration, instrument tracking and enhanced visualization. Virtual reality (VR) and augmented reality (AR) were compared in the last ten patients. Feasibility was determined with the sentinel nodes (SN) percentage that were successfully localized by navigation and validated ex vivo with the gamma probe.

Results: Per-protocol, the first ten patients were used for workflow optimization; the subsequent 20 patients were included in the analysis. Ultrasound registration was fast (7 min), accurate (0.1 cm) and intuitive. Tracked instruments were well-integrated and helped to localize precisely the SN (0.3 cm). Surgeons preferred VR while opening the resection path to find the SN and AR in proximity for exact localization. Using navigation, successful identification was achieved in 90% (45/50) SN. No navigation-related complications occurred.

Conclusions: Integrating ultrasound registration, instrument tracking and enhanced visualization during robot-assisted surgery has the potential to improve clinical use and localization of navigation in robot-assisted surgeries. These techniques allow to safely identify and remove pre-defined small pelvic lymph nodes in the pelvis.