A multimodal image guiding system for Navigated Ultrasound Bronchoscopy (EBUS): A human feasibility study

Abstract

BackgroundEndobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) is the endoscopic method of choice for confirming lung cancer metastasis to mediastinal lymph nodes. Precision is crucial for correct staging and clinical decision-making. Navigation and multimodal imaging can potentially improve EBUS-TBNA efficiency.AimsTo demonstrate the feasibility of a multimodal image guiding system using electromagnetic navigation for ultrasound bronchoschopy in humans.MethodsFour patients referred for lung cancer diagnosis and staging with EBUS-TBNA were enrolled in the study. Target lymph nodes were predefined from the preoperative computed tomography (CT) images. A prototype convex probe ultrasound bronchoscope with an attached sensor for position tracking was used for EBUS-TBNA. Electromagnetic tracking of the ultrasound bronchoscope and ultrasound images allowed fusion of preoperative CT and intraoperative ultrasound in the navigation software. Navigated EBUS-TBNA was used to guide target lymph node localization and sampling. Navigation system accuracy was calculated, measured by the deviation between lymph node position in ultrasound and CT in three planes. Procedure time, diagnostic yield and adverse events were recorded.ResultsPreoperative CT and real-time ultrasound images were successfully fused and displayed in the navigation software during the procedures. Overall navigation accuracy (11 measurements) was 10.0 ± 3.8 mm, maximum 17.6 mm, minimum 4.5 mm. An adequate sample was obtained in 6/6 (100%) of targeted lymph nodes. No adverse events were registered.ConclusionsElectromagnetic navigated EBUS-TBNA was feasible, safe and easy in this human pilot study. The clinical usefulness was clearly demonstrated. Fusion of real-time ultrasound, preoperative CT and electromagnetic navigational bronchoscopy provided a controlled guiding to level of target, intraoperative overview and procedure documentation.

Devices for image-guided lung interventions: State-of-the-art review

“…Research prototypes of navigation system: (a) the custom needle/sensor combination for TBNA, 58 (b) navigation bronchoscope with 6-DoF electromagnetic sensor, 59 (c) navigation forceps for biopsy, 60 (d) navigation bronchoscope, 61 and(e) electromagnetic navigation platform for bronchoscopy procedures. 63 …”

“…5d). 61 This group of researchers used a navigation system that they had previously developed for convex probe EBUS-TBNA. A prototype bronchoscope was used for the procedures and consisted of an Aurora EM tracking sensor attached close to the tip of a convex probe EBUS bronchoscope.…”

“…Gharagozloo et al 65 reported successfully Figure 5. Research prototypes of navigation system: (a) the custom needle/sensor combination for TBNA, 58 (b) navigation bronchoscope with 6-DoF electromagnetic sensor, 59 (c) navigation forceps for biopsy, 60 (d) navigation bronchoscope, 61 and (e) electromagnetic navigation platform for bronchoscopy procedures. 63 Another commercially available robot product for lung intervention is the robotic interventional radiologist assistance platform (MAXIO; Perfint Healthcare, Chennai, India) ( Figure 6(b)).…”

Passive Magnetic-Flux-Concentrator Based Electromagnetic Targeting System for Endobronchoscopy

“…It seems that the accuracy may not be sufficient for targeting. Nevertheless, when medical doctors use the targeting system in diagnosis, the medical doctors can always refer to the CT scan image of the bronchi tree anytime during the diagnosis [25,27]. By overlapping tumor’s/lesions’ locations in the CT scan image and targeted locations obtained by targeting system, the medical doctors are able to realize the actual moving path of the bronchoscope in the patient’s lung.…”

“…Recently, magnetic sensors [5,6,7,8,9,10,11,12,13,14,15] are developed for electromagnetic and magnetic navigating/targeting/tracking systems which become important alternative navigating/targeting/tracking approaches for surgical/clinical applications [16,17,18,19,20,21,22,23,24]. More recently, these magnetic sensor based electromagnetic navigations are integrated with standard EBUS as a hybrid system to perform a more accurate navigating/targeting endobronchoscope to target/locate lung tumors/lesions [25,26,27,28,29,30]. The system consists of a magnetic sensor attached on a distal-end of an EBUS convex probe (whose diameter is much bigger than a radial probe), a magnetic-sensors-module attached to the patient as a location reference, a huge magnetic-field generator, and an image/signal-processing module.…”