Navigated EBUS and Functional Imaging in Lung Cancer

Assessment of a Novel, Fast and Automatic CT-to-patient Registration Method During Navigated Bronchoscopy and Endobronchial Ultrasound Bronchoscopy (EBUS)

Electromagnetic navigation systems have proved feasible for precise intraoperative guiding during videobronchoscopy and endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA), based on maps made of preoperative CT images. PET--CT, PET--MRI and fMRI can point out malignant lesions. When fused into a research navigation system, functional imaging can add information of optimal sampling points in lung cancer staging. Correct image registration is then fundamental. This study is a build--on to NCT02493023, assessing the position and image registration accuracy and clinical feasibility of a multimodal image guiding system in patients referred for lung cancer staging by EBUS--TBNA.

A research navigation platform displays the intraoperative position of the endoscope inside the airways, and shows its position in 3D maps made from the patients' own preoperative images (PET-- CT, PET--MRI or fMRI). Images are acquired ahead of study inclusion. The navigation system acquires position data, first from a videobronchoscope, then from an EBUS--scope (same sort of output data acquired from both endoscopes) equipped with a position sensor for electromagnetic tracking. From intraoperative position data, the accuracy of the image--to--patient registration (for CT, PET--CT, PET--MRI and fMRI) and the navigation system accuracy are calculated. Electromagnetic navigation fused with available image modalities can be used to navigate directly and precisely to the area with highest suspicion of malignancy. Multimodal image guiding systems with functional imaging may thereby lead to improvements in endoscopic lung cancer staging, f. i. in diagnostic yield, procedure time and safety.

Endoscope position (measured in millimetres from origo in the x, y and z-plane) in 3 dimensional maps from preoperative CT, PET-CT, PET-MRI or fMRI images

intraoperative positional data of bronchoscope or endobronchial ultrasound scope (EBUS) measured and stored in navigation system software, used for registration and navigation system accuracy calculations

Diagnostic success per TBNA sample defined as >40 lymphocytes/high power field as reported by rapid onsite cytologist

Inclusion Criteria: referred to thoracic department St Olavs Hospital due to suspicion of lung cancer informed consent Exclusion Criteria: pregnancy

Sorger H, Hofstad EF, Amundsen T, Lango T, Leira HO. A novel platform for electromagnetic navigated ultrasound bronchoscopy (EBUS). Int J Comput Assist Radiol Surg. 2016 Aug;11(8):1431-43. doi: 10.1007/s11548-015-1326-7. Epub 2015 Nov 28.