In trans-oral surgeries, large intraoperative deformations limit the surgeons’ use of preoperative images to accurately resect tumors while traditional metal instruments render intraoperative images ineffective. A CT/MR compatible laryngoscopy system was developed previously to allow for the study of these deformations with intraoperative imaging. For this study, we compare the deformation analysis of two patient groups: those who had received prior radiation to the upper aerodigestive tract (irradiated) and those who have not (non-irradiated). We speculate that differences in tissue deformation exist between these two groups due to radiation-induced fibrosis (RIF) and that quantifying these distinct deformation patterns will lead to more patient-specific tissue modeling. Thirteen patients undergoing diagnostic laryngoscopy were recruited; five had been irradiated and eight had not. Artifact-free images were obtained and registered. Mandible, hyoid, and tongue region displacements were quantified. For the bony structures, significant differences were observed in certain displacement directions as well as magnitude, with the irradiated patient group experiencing less anatomical shift (non-irradiated vs irradiated: (Mandible) 12.6±3.6mm vs 7.9±2.8mm, p=0.029; (Hyoid) 13.3±3.1mm vs 9.0±1.8mm, p=0.019). For the tongue, average displacements of tongue fiducials were 26.2±11.1mm vs 22.9±8.4mm respectively (p=0.033). The data from this study can serve as ground truth to generate and evaluate upper aerodigestive tract deformation models to predict the intraoperative state and provide guidance to the surgeons.
Robot-assisted laparoscopic partial nephrectomies (RALPN) are performed to treat patients with locally confined renal carcinoma. There are well-documented benefits to performing partial (opposed to radical) kidney resections and to using robot-assisted laparoscopic (opposed to open) approaches. However, there are challenges in identifying tumor margins and critical benign structures including blood vessels and collecting systems during current RALPN procedures. The primary objective of this effort is to couple multiple image and data streams together to augment visual information currently provided to surgeons performing RALPN and ultimately ensure complete tumor resection and minimal damage to functional structures (i.e. renal vasculature and collecting systems). To meet this challenge we have developed a framework and performed initial feasibility experiments to couple pre-operative high-resolution anatomic images with intraoperative MRI, ultrasound (US) and optical-based surface mapping and kidney tracking. With these registered images and data streams, we aim to overlay the high-resolution contrast-enhanced anatomic (CT or MR) images onto the surgeon’s view screen for enhanced guidance. To date we have integrated the following components of our framework: 1) a method for tracking an intraoperative US probe to extract the kidney surface and a set of embedded kidney markers, 2) a method for co-registering intraoperative US scans with pre-operative MR scans, and 3) a method for deforming pre-op scans to match intraoperative scans. These components have been evaluated through phantom studies to demonstrate protocol feasibility.