Navigational Bronchoscopy for Early Lung Cancer: A Road to Therapy

Abstract

Peripheral lung nodules remain challenging for accurate localization and diagnosis. Once identified, there are many strategies for diagnosis with heterogeneous risk benefit analysis. Traditional strategies such as conventional bronchoscopy have poor performance in locating and acquiring the required tissue. Similarly, while computerized-assisted transthoracic needle biopsy is currently the favored diagnostic procedure, it is associated with complications such as pneumothorax and hemorrhage. Video-assisted thoracoscopic and open surgical biopsies are invasive, require general anesthesia and are therefore not a first-line approach. New techniques such as ultrathin bronchoscopy and image-based guidance technologies are evolving to improve the diagnosis of peripheral lung lesions. Virtual bronchoscopy and electromagnetic navigation systems are novel technologies based on assisted-computerized tomography images that guide the bronchoscopist toward the target peripheral lesion. This article provides a comprehensive review of these emerging technologies.

Keywords: Bronchoscopy; Computerized tomography (CT); Electromagnetic navigation; Image guidance; Lung cancer; Peripheral lung lesion; Respiratory.

Fig. 1

Virtual bronchoscopy navigation system. Real-time guidance with LungPoint^® Virtual Bronchoscopic Navigation simultaneously shows the virtual views and the navigation path. The dark pink area is the target selected as target 1. The blue line indicates the navigation path leading toward the target (courtesy Broncus LungPoint^®)

Fig. 2

Our electromagnetic navigation system [16, 25, 33, 34]. In our live porcine model, the essential components of an Electromagnetic Navigation System are labeled. a In a similar manner to Fig. 1, using preloaded data from a standard CT thorax, computer-based software provides virtual bronchoscopy images in a multiplanar working window (monitor screen). b An electromagnetic emitter and tracking board (green) creates a magnetic field around the chest (blue). c This allows tracking of a sensor probe in the extended working channel of a standard bronchoscope. Coupling of this system to the virtual bronchoscopic images guides movement of the probe to the target lesion. The placement of our probe in a flexible catheter allows passage of standard bronchoscopic instruments and biopsy. d Our research includes the investigation of automation and remote control of our sensor probe and catheter. EWC extended working channel

Fig. 3

Our electromagnetic navigation system multiplanar window. a Real-time bronchoscopy image and the sensor probe. b Virtual bronchoscopy image and the navigation pathway (green line) toward the target lesion. c 3D tracheobronchial anatomical model. d, e, f Axial, sagittal and coronal images displaying the sensor location in the computerized tomography images [25]

Fig. 4

An 81-year-old lady with bilateral lung nodules. Axial computerized tomography scan shows a positive bronchus sign [red arrow right upper lobe posterior segment (RB2)] related to a mass in her right upper lobe

Fig. 5

Bronchoscopic transparenchymal nodule access (courtesy Broncus Archimedes™). a Real-time bronchoscopic image showing catheter at the point of entry. b Real-time virtual image with point of entry overlaid. Green area indicates target lesion. The vertical colored lines on the left of the virtual bronchoscopy indicate the distance in the airway, tunnel length, size of the target and distance from the pleura. c Computerized tomography projections with target and vessel overlay. Red and blue colors indicate vessels. The target is marked green. d 3D reconstruction of the airway tree