Tracking of oral cavity carcinomas in head and neck surgery
NL: Tracken van mondholtecarcinomen tijdens hoofdhalschirurgie

Head and neck surgeons operate on a fine edge between radical resection of tumors and sparing of vital structures (e.g., arteries and nerves), visible only on specific preoperative scans (CT/MR). Identification of deep tumor margins inside the tongue is currently mainly based on palpation and experience/expertise of the surgeon because reliable quantitative feedback is lacking. As a result positive and suboptimal resections are common. By means of image-guided surgery, we can navigate the procedure by visualization of pre-operative planned MR and/or CT based 3D models and providing the surgeon with real-time feedback on the position of the surgical tool within this model and more important relative to the tumor margins. These innovations may allow to reduce both irradical resections and morbidity. This is the first study to use MR-based three-dimensional (3D) models of surgical resections for intra-operative navigation in head and neck surgery.

By means of image-guided surgery, we can navigate the procedure by visualization of pre-operative planned MR and/or CT based 3D models and providing the surgeon with real-time feedback on the position of the surgical tool within this model and more important relative to the tumor margins. These innovations may allow to reduce both irradical resections and morbidity.

Yearly update

The study includes 3 groups of tumor types, with different levels of complexity for navigation; group 1 are oral cavity carcinomas of the maxilla, group 2 are mandibular carcinomas, and group 3 are tongue carcinomas. This is to gather data, gain experience, examine feasibility, and accuracy in variations with different complexities. Prior to surgery, an CT/MR-based 3D model is constructed, containing the tumor (margins), anatomical structures, and vital structures within the area of resection. This model will be used as guidance during the surgery. At the start of the surgical procedure, electromagnetic sensors will be positioned externally on the head and, in case of mobile structures, such as the mandibular and the tongue, also at/nearby the tumor site. These EM sensors function as reference markers, which are used for intraoperative tracking. In addition, an intra operative XperCT-scan (for maxilla and mandibular patients) or an intra-operative 3D US scan (for tongue patients) of the patient will be acquired to provide a direct link between current position of the tumor and the location of the tumor and surrounding anatomy on the preoperative MR scan. Fusion of intra-operative XperCT/3D US and pre-operative MR images will allow us to visualize the exact position of the tumor within the oral cavity in an MR-based 3D model during surgery. During the surgical procedure, anatomical structures and the tumor margins can now be identified using a blunt EM-tracked probe of the navigation system.