Electromagnetic navigation bronchoscopy

Efficacy of Combining Multiple Electromagnetic Navigation Bronchoscopy Modalities for Diagnosing Lung Nodules

Electromagnetic navigation bronchoscopy (ENB) is one of the non-invasive methods used for lung nodule biopsy. We evaluated the efficacy of combining radial endobronchial ultrasound (R-EBUS)-guided transbronchial lung biopsy (TBLB) with ENB-guided TBLB or transbronchial needle aspiration (TBNA) for diagnosing lung nodules. Forty patients with a lung nodule underwent ENB-TBLB or TBNA, followed by R-EBUS-TBLB if available. The final diagnosis was benign or malignant, depending on the surgical pathology or 24-month follow-up computed tomography (CT). We compared the sensitivity, negative predictive value, and accuracy between combinations of procedures. The mean nodule size was 21.65 mm, and 60.0% of the nodules were solid. The bronchus was within the nodule in 67.5% and 65.0% of cases examined using CT and R-EBUS, respectively. The accuracies of ENB-TBLB alone, ENB-TBLB/TBNA, and R-EBUS-TBLB plus ENB-TBLB/TBNA were 74.4%, 82.5%, and 90.0%, respectively. The sensitivity levels of the aforementioned procedures were 69.8%, 78.8%, and 87.9%, respectively. Among 21 patients who underwent both ENB-TBLB and R-EBUS-TBLB, the latter revealed malignant cells in three of nine patients (33.3%) with benign ENB-TBLB results. Combined ENB-TBLB/TBNA and R-EBUS-TBLB had increased sensitivity and diagnostic accuracy for lung nodules. ENB and R-EBUS are complementary; using both modalities improves the sensitivity and accuracy of lung nodule diagnoses.

Application of endobronchial ultrasonography using a guide sheath and electromagnetic navigation bronchoscopy in the diagnosis of atypical bacteriologically-negative pulmonary tuberculosis

Background

In the absence of a positive sputum bacteriological result, pathological and bacteriological examinations of lung lesion biopsies are important methods to confirm bacteriological-negative tuberculosis. Endobronchial ultrasonography with guide sheath (EBUS-GS) and electromagnetic navigation bronchoscopy (ENB) are two new endobronchial diagnostic techniques, the combination of which has greatly facilitated the diagnosis of peripheral pulmonary lesions and is an especially useful, minimally invasive, effective diagnostic method for bacteriologically-negative tuberculosis cases.

Methods

A total of 78 patients were included in this study with suspected pulmonary tuberculosis based on clinical manifestations, laboratory tests, and imaging studies. The patients underwent a high-resolution chest CT scan before bronchoscopy, A method was selected (EBUS-GS alone, or EBUS-GS + ENB) based on the lesion site and the level and angle of the bronchus involved. After the lesion was found, a puncture needle, biopsy forceps, and brushing forceps were used to collect a tissue sample.

Results

Forty-four patients were diagnosed with tuberculosis; 1, nontuberculous Mycobacteria (NTM) lung disease; 15, lung cancer; 15, pulmonary infection; 1, allergic bronchopulmonary aspergillosis (ABPA); and 2, pneumoconiosis. A total of 25 patients of TB (56.8%) were successfully diagnosed with EBUS-GS plus ENB. Among the patients with confirmed diagnosis, 9 were diagnosed with pathological examination; 4, genetic analysis; 11, positive smear; and 14, positive culture.

Conclusions

The introduction of EBUS and ENB in China has provided a new direction for the diagnosis of atypical bacteriological-negative tuberculosis, as the techniques are less invasive and less expensive than thoracoscopy.

[Diagnostic Utility of Electromagnetic Navigation Bronchoscopy Combined with Radial Probe Endobronchial Ultrasound in Peripheral Pulmonary Lesions]

背景与目的

随着高分辨计算机断层扫描（computed tomography, CT）的广泛应用和健康体检的普遍开展，大量周围型肺部病灶被发现，对临床诊断治疗提出了新的挑战。电磁导航支气管镜（electromagnetic navigation bronchoscope, ENB）和径向探头支气管内超声（radial probe bronchoscopy ultrasound, R-EBUS）是用于周围型肺部病灶诊断的新兴技术，本研究旨在探讨ENB联合R-EBUS对肺周围型病灶诊断中的应用价值。

方法

2016年9月-2017年11月苏州大学附属第一医院胸外科应用ENB技术对18例患者的30处肺部周围型病灶进行了检查，术前制定导航计划，术中导航成功到达预定位置后使用R-EBUS确认病灶，依次使用穿刺针、细胞刷、活检钳进行病灶组织活检。

结果

30处肺部周围型病灶，导航成功率为100%（30/30），阳性诊断率为90%（27/30）。手术时间为（95.61±28.74）min，每处病灶导航时间为（25.90±11.29）min，发生气胸1例，未见其他严重并发症。

结论

利用ENB联合R-EBUS技术诊断肺周围型病灶具有较高的导航成功率和诊断阳性率，安全有效，值得进行临床推广。

The introduction of electromagnetic navigation bronchoscopy for the diagnosis of small pulmonary peripheral lesions in an Asian population

Background

Electromagnetic navigation bronchoscopy (ENB) is emerging as a useful new technique for diagnosing small pulmonary peripheral lesions (SPPLs). However, the accuracy and efficiency of ENB have not been investigated in Asian populations where the differential diagnoses for SPPLs may be different. To analyze this question, this study included patients who received diagnostic ENB followed by surgery for the excision of SPPLs.

Methods

Consecutive patients referred to the Department of Thoracic Surgery, Shanghai Pulmonary Hospital (Tongji University), between May 2014 and April 2015 were recruited. ENB was used to obtain biopsy tissue and make a diagnosis, which was then confirmed by histopathological examination.

Results

The ENB was performed on 84 SPPLs of 78 patients in the study, with four patients having more than one SPPL. It successfully reached and biopsied 81 lesions. The average ENB navigation time was 10.8 minutes (range, 0.5-52 minutes). No mortality occurred, with only two complications (one bleeding and one pneumothorax). The mean diameter of the biopsied SPPLs was 19.0 mm (range, 5.0-30.0 mm). The distance from the sensor probe to the focus was 8.0 mm (range, 1-16 mm). ENB diagnosis had identical results with histopathology examination in 81 lesions (37 lung cancer and 41 non-lung cancer). The sensitivity of ENB was 92.9% (78 out of 84 lesions) in this study.

Conclusions

These data suggested that ENB was an accurate and efficient procedure to sample and diagnose SPPLs in the Asian population. It appeared that ENB had a high percentage of successful results in both navigating and aiding in the diagnosis of SPPLs in the Asian population.

Improved targeting accuracy of lung tumor biopsies with scanning-beam digital x-ray tomosynthesis image guidance

PURPOSE

Electromagnetic navigation bronchoscopy (ENB) provides improved targeting accuracy during transbronchial biopsies of suspicious nodules. The greatest weakness of ENB-based guidance is the registration divergence that exists between the planning CT, acquired days or weeks before the intervention, and the patient on the table on the day of the intervention. Augmenting ENB guidance with real-time tomosynthesis imaging during the intervention could mitigate the divergence and further improve the yield of ENB-guided transbronchial biopsies. The real-time tomosynthesis prototype, the scanning-beam digital x-ray (SBDX) system, does not currently display images reconstructed by the iterative algorithm that was developed for this lung imaging application. A protocol using fiducial markers was therefore implemented to permit evaluation of potential improvements that would be provided by the SBDX system in a clinical setting.

METHODS

Ten 7 mm lesions (5 per side) were injected into the periphery of each of four preserved pig lungs. The lungs were then placed in a vacuum chamber that permitted simulation of realistic motion and deformation due to breathing. Standard clinical CT scans of the pig lung phantoms were acquired and reconstructed with isotropic resolution of 0.625 mm. Standard ENB-guided biopsy procedures including target identification, path planning, CT-to-lung registration and navigation to the lesion were carried out, and a fiducial marker was placed at the location at which a biopsy would have been acquired. The channel-to-target distance provided by the ENB system prior to fiducial placement was noted. The lung phantoms were then imaged using the SBDX system, and using high-resolution conebeam CT. The distance between the fiducial marker tip and the lesion was measured in SBDX images and in the gold-standard conebeam-CT images. The channel-to-target divergence predicted by the ENB system and measured in the SBDX images was compared to the gold standard to determine if improved targeting accuracy could be achieved using SBDX image guidance.

RESULTS

As expected, the ENB system showed poorer targeting accuracy for small peripheral nodules. Only 20 nodules of the 40 injected could be adequately reached using ENB guidance alone. The SBDX system was capable of visualizing these small lesions, and measured fiducial-to-target distances on SBDX agreed well with measurements in gold-standard conebeam-CT images (p = 0.0001). The correlation between gold-standard conebeam-CT distances and predicted fiducial-to-target distances provided by the ENB system was poor (p = 0.72), primarily due to inaccurate ENB CT-to-body registration and movement due to breathing.

CONCLUSIONS

The SBDX system permits visualization of small lung nodules, as well as accurate measurement of channel-to-target distances. Combined use of ENB with SBDX real-time image guidance could improve accuracy and yield of biopsies, particularly of those lesions located in the periphery of the lung.

Electromagnetic navigated positioning of the maxilla after Le Fort I osteotomy in preclinical orthognathic surgery cases

OBJECTIVES

Inaccuracies in orthognathic surgery can be caused during face-bow registration, model surgery on plaster models, and intermaxillary splint manufacturing. Electromagnetic (EM) navigation is a promising method for splintless digitized maxillary positioning.

STUDY DESIGN

After performing Le Fort I osteotomy on 10 plastic skulls, the target position of the maxilla was guided by an EM navigation system. Specially implemented software illustrated the target position by real-time multistage colored three-dimensional imaging. Accuracy was determined by using pre- and postoperative cone beam computed tomography.

RESULTS

The high accuracy of the EM system was underlined by the fact that it had a navigated maxilla position discrepancy of only 0.4 mm, which was verified by postoperative cone beam computed tomography.

CONCLUSIONS

This preclinical study demonstrates a precise digitized approach for splintless maxillary repositioning after Le Fort I osteotomy. The accuracy and intuitive illustration of the introduced EM navigation system is promising for potential daily use in orthognathic surgery.

Approach to intraoperative electromagnetic navigation in orthognathic surgery: A phantom skull based trial

INTRODUCTION

Intraoperative guidance using electromagnetic navigation is an upcoming method in maxillofacial surgery. However, due to their unwieldy structures, especially the line-of-sight problem, optical navigation devices are not used for daily orthognathic surgery. Therefore, orthognathic surgery was simulated on study phantom skulls, evaluating the accuracy and handling of a new electromagnetic tracking system.

MATERIAL AND METHODS

Le-Fort I osteotomies were performed on 10 plastic skulls. Orthognathic surgical planning was done in the conventional way using plaster models. Accuracy of the gold standard, splint-based model surgery versus an electromagnetic tracking system was evaluated by measuring the actual maxillary deviation using bimaxillary splints and preoperative and postoperative cone beam computer tomography imaging. The distance of five anatomical marker points were compared pre- and postoperatively.

RESULTS

The electromagnetic tracking system was significantly more accurate in all measured parameters compared with the gold standard using bimaxillary splints (p < 0.01). The data shows a discrepancy between the model surgical plans and the actual correction of the upper jaw of 0.8 mm. Using the electromagnetic tracking, we could reduce the discrepancy of the maxillary transposition between the planned and actual orthognathic surgery to 0.3 mm on average.

DISCUSSION

The data of this preliminary study shows a high level of accuracy in surgical orthognathic performance using electromagnetic navigation, and may offer greater precision than the conventional plaster model surgery with bimaxillary splints.

CONCLUSION

This preliminary work shows great potential for the establishment of an intraoperative electromagnetic navigation system for maxillofacial surgery.

Electromagnetic tracking in medicine--a review of technology, validation, and applications

Object tracking is a key enabling technology in the context of computer-assisted medical interventions. Allowing the continuous localization of medical instruments and patient anatomy, it is a prerequisite for providing instrument guidance to subsurface anatomical structures. The only widely used technique that enables real-time tracking of small objects without line-of-sight restrictions is electromagnetic (EM) tracking. While EM tracking has been the subject of many research efforts, clinical applications have been slow to emerge. The aim of this review paper is therefore to provide insight into the future potential and limitations of EM tracking for medical use. We describe the basic working principles of EM tracking systems, list the main sources of error, and summarize the published studies on tracking accuracy, precision and robustness along with the corresponding validation protocols proposed. State-of-the-art approaches to error compensation are also reviewed in depth. Finally, an overview of the clinical applications addressed with EM tracking is given. Throughout the paper, we report not only on scientific progress, but also provide a review on commercial systems. Given the continuous debate on the applicability of EM tracking in medicine, this paper provides a timely overview of the state-of-the-art in the field.

Multimodality image fusion-guided procedures: technique, accuracy, and applications

Personalized therapies play an increasingly critical role in cancer care: Image guidance with multimodality image fusion facilitates the targeting of specific tissue for tissue characterization and plays a role in drug discovery and optimization of tailored therapies. Positron-emission tomography (PET), magnetic resonance imaging (MRI), and contrast-enhanced computed tomography (CT) may offer additional information not otherwise available to the operator during minimally invasive image-guided procedures, such as biopsy and ablation. With use of multimodality image fusion for image-guided interventions, navigation with advanced modalities does not require the physical presence of the PET, MRI, or CT imaging system. Several commercially available methods of image-fusion and device navigation are reviewed along with an explanation of common tracking hardware and software. An overview of current clinical applications for multimodality navigation is provided.

Photodynamic therapy (PDT) for lung cancer

Clinical PDT began in the early 1980s and lung cancer was one of the first indications for which the procedure was tried. Initially patients with advanced inoperable cancer and major bronchial obstruction were targeted with the objective of relief of airway obstruction and symptom palliation. In the past 30 years, assisted by progress in imaging methods and advances of technological developments, PDT indications have expanded to incorporate a multitude of lung cancer presentations which this review aims to display. Locally advanced and early stage endobronchial cancer continues to be the major indications albeit with a more precise diagnostic and guided illumination devices. Peripheral parenchymal disease has been a technical challenge but there is still ongoing development. Multifocal synchronous, recurrence and metachronous endobronchial disease following lung resection are now an up and coming indication with rewarding outcome. More importantly PDTs role within a multi-disciplinary assault on lung cancer is receiving acceptance.