Furthering Precision in Sentinel Node Navigational Surgery for Oral Cancer: a Novel Triple Targeting System

To describe an innovative sentinel lymph node (SLN) guidance approach using a radionuclide tracer, 3D augmented reality-guided imaging, and near infrared (NIR) fluorescence over-lay imaging with hand-held probes to optimize accuracy, efficiency, and precise navigation for sentinel node (SN) localization in head and neck cancer. In a cT1N0M0 squamous cell carcinoma of the tongue, pre-operative radionuclide lymphoscintigraphy was performed with a sentinel node-specific radiolabeled tracer. Intraoperatively, a 3D hand-held augmented reality (AR) scanning SPECT probe assessed concordance of the SN with pre-operative SPECT-CT images. The real-time optical video was linked to the SPECT-CT images for added precision. Final guidance to the SN was performed using ICG fluorescence imaging. Dynamic and SPECT-CT showed bilateral lymphatic drainage from the tumor. The 3D hand-held AR SPECT probe SN localization was concordant with pre-operative imaging. The optical video successfully demonstrated the lymphatic drainage in real-time through a unique overlay fluorescence image. The ICG localized to the same nodes identified by both the SPECT-CT and hand-held SPECT images. The use of dual radiation and fluorescence tracers improved SN detection, especially for SN close to the injection site. The hand-held probes allowed the surgeon to dissect continuously, without needing to change tools. The combination of augmented reality, nuclear medicine, and over-lay fluorescence imaging allowed greater accuracy for matching the preoperative imaging with intraoperative identification and precisely guiding the dissection. This method uniquely permitted the surgeon to efficiently dissect the SN with accurate visualization and optimal precision.