Electromagnetic navigation diagnostic bronchoscopy: a prospective study

A bronchoscopic navigation method based on neural radiation fields

PURPOSE

We introduce a novel approach for bronchoscopic navigation that leverages neural radiance fields (NeRF) to passively locate the endoscope solely from bronchoscopic images. This approach aims to overcome the limitations and challenges of current bronchoscopic navigation tools that rely on external infrastructures or require active adjustment of the bronchoscope.

METHODS

To address the challenges, we leverage NeRF for bronchoscopic navigation, enabling passive endoscope localization from bronchoscopic images. We develop a two-stage pipeline: offline training using preoperative data and online passive pose estimation during surgery. To enhance performance, we employ Anderson acceleration and incorporate semantic appearance transfer to deal with the sim-to-real gap between training and inference stages.

RESULTS

We assessed the viability of our approach by conducting tests on virtual bronchscopic images and a physical phantom against the SLAM-based methods. The average rotation error in our virtual dataset is about 3.18∘ and the translation error is around 4.95 mm. On the physical phantom test, the average rotation and translation error are approximately 5.14∘ and 13.12 mm.

CONCLUSION

Our NeRF-based bronchoscopic navigation method eliminates reliance on external infrastructures and active adjustments, offering promising advancements in bronchoscopic navigation. Experimental validation on simulation and real-world phantom models demonstrates its efficacy in addressing challenges like low texture and challenging lighting conditions.

Single Institution Evaluation of Electromagnetic Navigation Bronchoscopy for Diagnosis of Pulmonary Lesions

BACKGROUND

Electromagnetic navigation bronchoscopy (ENB) utilizes three-dimensional reconstructions based on computed tomography to guide the biopsy of pulmonary lesions. Various limitations have been described; however, supporting data have been limited by small sample sizes.

METHODS

Cases of ENB for evaluation of a pulmonary lesion at a single institution during a 1-year span were reviewed for demographics, lesion location, procedural details, and final tissue diagnosis. ENB was performed by 3 pulmonologists using the Veran platform with rapid on-site evaluation. T test or Mann-Whitney U test compared continuous variables and χ 2 or Fisher exact test compared categorical variables as appropriate. A patient with a negative or inconclusive biopsy was followed for 1 year postprocedure.

RESULTS

A total of 107 pulmonary lesions were evaluated. The population studied had a mean age of 67 and a median pulmonary lesion size of 26.0 mm. For malignant lesions, the pathologic diagnostic yield from ENB was 52.1% (37/71). The diagnostic yield of benign lesions was much lower at 16.7% (6/36). The overall procedural complication rate was 8.4% (9/107). Complications were more likely to occur in patients with malignant lesions. The most common complication was pneumothorax, occurring in 5.6% of all biopsies and 7.0% of patients with malignant lesions.

CONCLUSION

This study demonstrates significant differences in diagnostic accuracy between lesions found to be malignant versus benign. Our observed complication rate was slightly higher than other groups have reported, with a greater frequency occurring in patients with malignant lesions; however, the rate of pneumothorax was still lower than computed tomography-guided transcutaneous biopsies.

Utility of auto fluorescence-guided biopsy in suspected lung cancer patients with bronchial mucosal lesions

BACKGROUND

Bronchoscopy is currently the most common technique for lung cancer diagnosis. Patients suspected of malignancy often undergo bronchoscopic examination, and biopsy is routinely used in patients with visible bronchial lesions. However, it is difficult to differentially diagnose lung cancer in patients with bronchial mucosal lesions. Thus, this study was conducted to investigate the utility of fluorescence-guided biopsy in suspected lung cancer patients with bronchial mucosal lesions.

METHODS

We conducted a retrospective study in a single screening center to assess the sensitivity and specificity of fluorescence-guided biopsy compared with white light bronchoscopy (WLB) in patients with bronchial mucosal lesions.

RESULTS

A total of 301 patients with bronchial mucosal lesions were enrolled in this study. The sensitivity for patients with fluorescence-guided biopsy was 60.3 % (95 % confidence interval [CI]: 53.1 %-67.1 %), which was higher than that of patients with WLB alone (45.2 %, 95 % CI: 38.2-52.4 %) (P = 0.0026). Additionally, compared with the WLB group, the fluorescence -guided biopsy group was found to have a significantly higher specificity (100 %, 95 % CI: 95.5-100 % versus 69.6 %, 95 % CI: 59.6-78.1 %), positive predictive value (100 %, 95 % CI: 96.1-100 % versus 74.3 %, 95 % CI: 65.5-81.7 %) and negative predictive value (56.3 %, 95 % CI: 48.8-63.6 % versus 39.4 %, 95 % CI: 32.3-47.0 %).

CONCLUSION

Fluorescence-guided biopsy can serve as an important adjunct to WLB for the differential diagnosis of lung cancer in patients with bronchial mucosal lesions.

Electromagnetic Navigational Bronchoscopy Learning Curve Regarding Pneumothorax Rate and Diagnostic Yield

Electromagnetic navigational bronchoscopy (ENB) has emerged as an innovative technique for diagnosing peripheral and central nodules, offering an improved diagnostic yield compared to conventional bronchoscopy with fewer complications. That being said, pneumothorax remains a frequent complication. This retrospective study conducted at Castle Hill Hospital, UK, analysed ENB procedures over four years to assess the diagnostic yield and pneumothorax rates, exploring learning curves and procedural improvements specifically focusing on the diagnostic yield and pneumothorax rate as markers of change. A total of 246 patients underwent 358 peripheral lung biopsies, revealing an overall diagnostic yield of 61.3%. The diagnostic yield increased from 58.2% in 2020-2021 to 66.0% in 2022-2023 while the pneumothorax rate decreased significantly from 9.8% to 3.4% (p = 0.021*). The majority of pneumothorax cases occurred following upper lobe procedures. The study depicts the importance of procedural experience in improving outcomes, suggesting a learning curve effect. Additionally, it emphasizes the potential for technological advancements, such as robotic assistance, to mitigate operator-dependent variability and improve reproducibility in ENB procedures. These findings contribute to optimizing diagnostic pathways for lung lesions and improving patient safety in ENB interventions.

Robotic-assisted Navigation Bronchoscopy: A Meta-Analysis of Diagnostic Yield and Complications

BACKGROUND

Robotic-assisted navigation bronchoscopy (RANB) is a novel method to biopsy lung nodules, with initial reports demonstrating excellent accuracy. We aimed to evaluate pooled estimates of diagnostic yields and complication rates with RANB by performing a meta-analysis of the available literature.

METHODS

We searched 3 databases, including PubMed, EmBase, and Web of Science. The resulting abstracts were reviewed by 2 investigators. Analyses were performed using random effects models, and diagnostic yield and complication rates were estimated after the Freeman-Tukey transformation.

RESULTS

A total of 23 articles, comprising 1409 patients and 1541 nodules, were included in the final analysis. Mean ages ranged from 63.2 to 69.3 years. The average size of the nodules ranged between 5.9 and 25.0 mm. Most patients (54.0% to 92.0%) had a current or prior smoking history in studies that reported them (n=8). The pooled diagnostic yield was 81.9% (12 studies, 838 nodules, 95% CI: 83.4%-91.0%), and the pooled sensitivity for malignancy was 87.6% (8 studies, 699 nodules, 95% CI: 81.3%-89.5%). The pooled incidence of pneumothorax rates was 0.60% (95% CI: 0.11%-1.35%). The pooled incidence of major bleeding was <0.01%.

CONCLUSION

Diagnostic yield for patients with pulmonary nodules undergoing RANB is high, though may be impacted by the prevalence of malignancy, participant selection, and publication bias. Complication rates, including pneumothoraces and bleeding rates, appear low across all studies. If RANB is available, clinicians should consider utilizing this platform to biopsy pulmonary nodules.

The effect of combining different sampling tools on the performance of electromagnetic navigational bronchoscopy for the evaluation of peripheral lung lesions and factors associated with its diagnostic yield

BACKGROUND

We assessed the performance of Electromagnetic navigational bronchoscopy (ENB) as a standalone diagnostic technique and the performance of different sampling tools used during the procedure.

METHODS

We recruited 160 consecutive patients who underwent ENB for peripheral lung lesions (PLL) at a tertiary care centre. The diagnostic performance of ENB and sampling tools was assessed using a logistic regression model and a ROC-curve in which the dependent variable was diagnostic success. A multivariate model was built to predict diagnostic success before performing ENB to select the best candidates for the procedure.

RESULTS

Most patients with PLLs in the study were male (65%), with a mean age of 67.9 years. The yield was 66% when the most common techniques were used together as suction catheter + transbronchial biopsy forceps (TBBx) + bronchoalveolar lavage + bronchial washing (p < 0.001) and increased to 69% when transbronchial needle aspiration (TBNA) and cytology brush were added (p < 0.001). Adding diagnostic techniques such as TBBx and TBNA resulted in an increase in diagnostic performance, with a statistically significant trend (p = 0.002). The logistic model area-under the ROC-curve for diagnostic success during ENB was 0.83 (95% CI:0.75-0.90; p < 0.001), and a logit value ≥ 0.12 was associated with ≥ 50% probability of diagnostic success.

CONCLUSIONS

ENB, as a stand-alone diagnostic tool for the evaluation of PLLs when performed by experienced operators using a multi-modality technique, has a good diagnostic yield. The probability of having a diagnostic ENB could be assessed using the proposed model.

Outcomes of the electromagnetic navigation bronchoscopy using forceps for lung lesion suspected malignancy: A retrospective study

Many studies have reported electromagnetic navigation bronchoscopy (ENB) diagnostic yields and the importance of size and computed tomography (CT) bronchus sign. This study aimed to determine the diagnostic yield of ENB alone, using forceps biopsy and cytology. We analyzed the factors associated with yield and complications according to gross specimen size. This retrospective study included patients who underwent ENB using forceps for suspected lung lesions on CT between January 2020 and December 2022 in South Korea. Factors related to the ENB diagnostic yield and complications were evaluated, and the impacts of gross specimen size and cytology were analyzed. A total of 276 patients were analyzed. The final diagnostic yield was 75.5% after excluding indeterminate cases. Sensitivity and specificity were 74.2% and 100%, respectively. Pneumothorax developed in 1.4% (4/276) of cases, with no grade 3 or higher bleeding. Univariable analysis showed that the number of biopsies and the size of the gross specimen were related to the diagnosis. Multivariable analyses showed that a larger lesion size on CT was a significant factor for diagnosis. The gross size of the specimens was not significantly associated with epinephrine use. ENB had acceptable diagnostic yield and safety for diagnosing lung lesions with suspected malignancy. Obtaining more tissue through biopsy may not increase bleeding or pneumothorax complications. Identifying patients with lesion characteristics, including CT bronchus sign, would help increase ENB diagnostic yield.

Endobronchial ultrasound: a pictorial essay

BACKGROUND AND AIM

endobronchial ultrasound has gained widespread popularity in the last decade, becoming the primary technique for minimally invasive evaluation of the mediastinum and staging of lung cancer. Several tertiary and quaternary care institutes use this method, performed by trained and accredited specialists. Its main indications are (I) diagnosis and staging of lung cancer, (II) mediastinal lymphadenopathy diagnosis (III) sampling peripheral pulmonary lesions.

CONCLUSIONS

this manuscript aims to describe the operational potential of both convex endobronchial ultrasound probe and radial endobronchial ultrasound probe technology, focusing on lung cancer. This narrative review is complemented with by the description of peculiar clinical cases in which endobronchial ultrasound played a pivotal role in reaching the diagnosis.

Single Setting Robotic Lung Nodule Diagnosis and Resection

Lung cancer remains the leading cause of cancer-related deaths. Early tissue diagnosis followed by timely therapeutic procedures can have a significant impact on overall survival. While robotic-assisted lung resection is an established therapeutic procedure, robotic-assisted bronchoscopy is a more recent diagnostic procedure that improves reach, stability, and precision in the field of bronchoscopic lung nodule biopsy. The ability to combine lung cancer diagnostics with therapeutic surgical resection into a single-setting anesthesia procedure has the potential to decrease costs, improve patient experiences, and most importantly, reduce delays in cancer care.

Guided Bronchoscopy for the Evaluation of Pulmonary Lesions: An Updated Meta-analysis

BACKGROUND

Guided bronchoscopy is increasingly used to diagnose peripheral pulmonary lesions (PPLs). A meta-analysis published in 2012 demonstrated a pooled diagnostic yield of 70%; however, recent publications have documented yields as low as 40% and as high as 90%.

RESEARCH QUESTION

Has the diagnostic yield of guided bronchoscopy in patients with PPLs improved over the past decade?

STUDY DESIGN AND METHODS

A comprehensive search was performed of studies evaluating the diagnostic yield of differing bronchoscopic technologies used to reach PPLs. Study quality was assessed using the Quality assessment of diagnostic accuracy of studies (QUADAS-2) assessment tool. Number of lesions, type of technology used, overall diagnostic yield, and yield by size were extracted. Adverse events were recorded. Meta-analytic techniques were used to summarize findings across all studies.

RESULTS

A total of 16,389 lesions from 126 studies were included. There was no significant difference in diagnostic yield prior to 2012 (39 studies; 3,052 lesions; yield 70.5%) vs after 2012 (87 studies; 13,535 lesions; yield 69.2%) (P > .05). Additionally, there was no significant difference in yield when comparing different technologies. Studies with low risk of overall bias had a lower diagnostic yield than those with high risk of bias (66% vs 71%, respectively; P = .018). Lesion size > 2 cm, presence of bronchus sign, and reports with a high prevalence of malignancy in the study population were associated with significantly higher diagnostic yield. Significant (P < .0001) between-study heterogeneity was also noted.

INTERPRETATION

Despite the reported advances in bronchoscopic technology to diagnose PPLs, the diagnostic yield of guided bronchoscopy has not improved.

Diagnostic yield and safety of navigation bronchoscopy: A systematic review and meta-analysis

BACKGROUND

Navigation bronchoscopy has seen rapid development in the past decade in terms of new navigation techniques and multi-modality approaches utilizing different techniques and tools. This systematic review analyses the diagnostic yield and safety of navigation bronchoscopy for the diagnosis of peripheral pulmonary nodules suspected of lung cancer.

METHODS

An extensive search was performed in Embase, Medline and Cochrane CENTRAL in May 2022. Eligible studies used cone-beam CT-guided navigation (CBCT), electromagnetic navigation (EMN), robotic navigation (RB) or virtual bronchoscopy (VB) as the primary navigation technique. Primary outcomes were diagnostic yield and adverse events. Quality of studies was assessed using QUADAS-2. Random effects meta-analysis was performed, with subgroup analyses for different navigation techniques, newer versus older techniques, nodule size, publication year, and strictness of diagnostic yield definition. Explorative analyses of subgroups reported by studies was performed for nodule size and bronchus sign.

RESULTS

A total of 95 studies (n = 10,381 patients; n = 10,682 nodules) were included. The majority (n = 63; 66.3%) had high risk of bias or applicability concerns in at least one QUADAS-2 domain. Summary diagnostic yield was 70.9% (95%-CI 68.4%-73.2%). Overall pneumothorax rate was 2.5%. Newer navigation techniques using advanced imaging and/or robotics(CBCT, RB, tomosynthesis guided EMN; n = 24 studies) had a statistically significant higher diagnostic yield compared to longer established techniques (EMN, VB; n = 82 studies): 77.5% (95%-CI 74.7%-80.1%) vs 68.8% (95%-CI 65.9%-71.6%) (p < 0.001).Explorative subgroup analyses showed that larger nodule size and bronchus sign presence were associated with a statistically significant higher diagnostic yield. Other subgroup analyses showed no significant differences.

CONCLUSION

Navigation bronchoscopy is a safe procedure, with the potential for high diagnostic yield, in particular using newer techniques such as RB, CBCT and tomosynthesis-guided EMN. Studies showed a large amount of heterogeneity, making comparisons difficult. Standardized definitions for outcomes with relevant clinical context will improve future comparability.

Robotic bronchoscopy: potential in diagnosing and treating lung cancer

INTRODUCTION

Lung cancer remains the deadliest form of cancer in the world. Screening through low-dose CT scans has shown improved detection of pulmonary nodules; however, with the introduction of robotic bronchoscopy, accessing and biopsying peripheral pulmonary nodules from the airway has expanded. Improved diagnostic yield through enhanced navigation has made robotic bronchoscopy an ideal diagnostic technology for many proceduralists. Studies have demonstrated that robotic bronchoscopes can reach further with improved maneuverability into the distal airways compared to conventional bronchoscopes.

AREAS COVERED

This review paper highlights the literature on the technological advancements associated with robotic bronchoscopy and the future directions the field of interventional pulmonary may utilize this modality for in the treatment of lung cancer. Referenced articles were included at the discretion of the authors after a database search of the particular technology discussed.

EXPERT OPINION

As the localization of target lesions continues to improve, robotic platforms that provide reach, stability, and accuracy paves the way for future research in endoluminal treatment for lung cancer. Future studies with intratumoral injection of chemotherapy and immunotherapy and ablation modalities are likely to come in the coming years.

[Diagnostic Value and Safety of Electromagnetic Navigation Bronchoscopy in Peripheral Pulmonary Lesions: A Meta-analysis]

BACKGROUND

The incidence and mortality of lung cancer have always been at the forefront of malignant tumors. With the development of lung cancer detection techniques, more peripheral pulmonary lesions (PPLs) have been detected. The diagnostic accuracy of procedures for PPLs keeps controversial. This study aims to systematically evaluate the diagnostic value and the safety of electromagnetic navigation bronchoscopy (ENB) in the diagnosis of PPLs.

METHODS

The relevant literatures in the diagnostic yield of PPLs by ENB were systematically retrieved from Wanfang Data Knowledge Service Platform, China National Knowledge Infrastructure, Embase, PubMed, Cochrane Library and Web of Science. The software of Stata 16.0, RevMan 5.4 and Meta-disc 1.4 were used to conduct the meta-analysis.

RESULTS

A total of 54 literatures with 55 studies were included in our meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio of ENB in the diagnosis of PPLs were 0.77 (95%CI: 0.73-0.81), 0.97 (95%CI: 0.93-0.99), 24.27 (95%CI: 10.21-57.67), 0.23 (95%CI: 0.19-0.28) and 104.19 (95%CI: 41.85-259.37), respectively. The area under curve (AUC) was 0.90 (95%CI: 0.87-0.92). Meta-regression and subgroup analyses indicated that the potential heterogeneity resulted from study type, additional localization techniques, sample size, lesion size and type of sedation. The use of additional localization techniques and general anesthesia have improved the diagnostic efficiency of ENB in PPLs. The incidence of adverse reactions and complications associated with ENB was very low.

CONCLUSIONS

ENB provides well diagnostic accuracy and safety.

Robotics in the diagnosis and staging of lung cancer

The diagnosis of peripheral small lung lesions by electromagnetic navigational bronchoscopy is still inferior to computed tomography (CT) guided percutaneous transthoracic needle lung biopsy. Robotic bronchoscopy is a new technology that may be a potential breakthrough in the diagnosis of small lung lesions. Real-time tools such as electromagnetic navigation, radial-endobronchial ultrasound, and cone beam CT may further improve the diagnostic yield rate may further improve the diagnostic yield rate. In this article, we reviewed early experience of robotic bronchoscopy for diagnosis and staging of lung cancer.

Robotic Bronchoscopy: Review of Three Systems

Robotic bronchoscopy (RB) has been shown to improve access to smaller and more peripheral lung lesions, while simultaneously staging the mediastinum. Pre-clinical studies demonstrated extremely high diagnostic yields, but real-world RB yields have yet to fully matched up in prospective studies. Despite this, RB technology has rapidly evolved and has great potential for lung-cancer diagnosis and even treatment. In this article, we review the historical and present challenges with RB in order to compare three RB systems.

Diagnostic performance of cryobiopsy guided by radial-probe EBUS with a guide sheath for peripheral pulmonary lesions

OBJECTIVE

Transbronchial lung cryobiopsy (TBCB) has developed rapidly and has become one of the research hotspots of lung biopsy technology. The present study sought to evaluate the efficacy of TBCB guided by radial-probe EBUS (RP-EBUS) and a guide sheath (GS) without fluoroscopy for peripheral pulmonary lesions.

METHODS

In this retrospective study, McNemar's test was used in order to compare TBCB and transbronchial forceps biopsy (TBFB) in terms of diagnostic performance. A multivariate logistic regression model was designed to explore the association between predictive variables and the diagnostic yield of TBCB.

RESULTS

A total of 168 patients underwent GS-guided RP-EBUS. Of those, 157 had lesions that were visible and 11 had lesions that were not. Of those 157 patients, 24 were excluded because of missing data or an unclear final diagnosis. Therefore, 133 patients underwent RP-EBUS-GS-guided TBFB and TBCB. The pooled diagnostic yield of RP-EBUS-GS-guided TBCB without fluoroscopy was 71.5% (103/144). In 133 patients, the diagnostic yield of TBCB was significantly higher than that of TBFB (77.4% vs. 59.4%; p < 0.05). Multivariate analysis indicated that lesion size and site were independently associated with the diagnostic yield of TBCB (OR = 2.8, p = 0.03 and OR = 4.1, p = 0.01, respectively), although cryoprobe size was not. There was no significant difference between the 1.1-mm cryoprobe and the 1.9-mm cryoprobe in terms of diagnostic performance (78.4% vs. 76.8%; p > 0.05).

CONCLUSIONS

GS-guided RP-EBUS is regarded as a practical option for guiding cryobiopsy, although it may not be able to replace fluoroscopy. Peripheral pulmonary lesions not located in the upper lobes or larger than 30 mm are significantly associated with a higher diagnostic yield of cryobiopsy.

When Pulmonologists Are Novice to Navigational Bronchoscopy, What Predicts Diagnostic Yield?

Predicting factors of diagnostic yield in electromagnetic navigation bronchoscopy (ENB) have been explored in a number of previous studies based on data from experienced operators. However, little is known about predicting factors when the procedure is carried out by operators in the beginning of their learning curve. We here aim to identify the role of operators' experience as well as lesion- and procedure characteristics on diagnostic yield of ENB procedures in the hands of novice ENB operators. Four operators from three centers without prior ENB experience were enrolled. The outcome of consecutive ENB procedures was assessed and classified as either diagnostic or non-diagnostic and predicting factors of diagnostic yield were assessed. A total of 215 procedures were assessed. A total of 122 (57%) of the ENB procedures resulted in diagnostic biopsies. Diagnostic ENB procedures were associated with a minor yet significant difference in tumor size compared to non-diagnostic/inconclusive ENB procedures (28 mm vs. 24 mm; p = 0.03). Diagnostic ENB procedures were associated with visible lesions at either fluoroscopy (p = 0.003) or radial endobronchial ultrasound (rEBUS), (p = 0.001). In the logistic regression model, lesion visibility on fluoroscopy, but none of operator experience, the presence of a bronchus sign, lesion size, or location nor visibility on rEBUS significantly impacted the diagnostic yield. In novice ENB operators, lesion visibility on fluoroscopy was the only factor found to increase the chance of obtaining a diagnostic sample.

Nodules, Navigation, Robotic Bronchoscopy, and Real-Time Imaging

The process of detection, diagnosis, and management of lung nodules is complex due to the heterogeneity of lung pathology and a relatively low malignancy rate. Technological advances in bronchoscopy have led to less-invasive diagnostic procedures and advances in imaging technology have helped to improve nodule localization and biopsy confirmation. Future research is required to determine which modality or combination of complimentary modalities is best suited for safe, accurate, and cost-effective management of lung nodules.

Outcomes of a Newly Established Electromagnetic Navigation Bronchoscopy Service in the Middle East

Aims:

Electromagnetic Navigation Bronchoscopy (EMNB) is a useful tool for the bronchoscopist to target peripheral pulmonary lesions. It has a well-established efficacy and safety profile; however, there are no studies describing its utility in a Middle Eastern population. In this paper, we describe the efficacy and safety outcomes of a newly established EMNB service.

Background:

The diagnosis of peripheral pulmonary lesions presents a significant challenge to the bronchoscopist, especially in the era of increased thoracic imaging with computerized tomography (CT) scans. EMNB is a relatively novel technique that utilizes an image-guided localization system akin to Global Positioning Satellite (GPS) technology, offering the bronchoscopist an accurate navigational pathway to sample peripheral pulmonary targets.

Objective:

We present our initial experience of performing EMNB and report our diagnostic and safety outcomes with EMN bronchoscopy.

Methods:

We conducted a retrospective review of the medical notes of all patients booked for EMNB from May 2015 to December 2019 at our tertiary care center using the electronic medical record system.

Results and Discussion:

Fifty-five patients were scheduled for EMNB, and 47 patients (24 males, 23 females) had EMNB-guided sampling between May 2015 and December 2019. The median age of the patients was 61 years (IQR 49.5-74.3). A bronchus sign was present on the CT chest in 29 (61.7%) cases. Thirty-one (66%) patients had positive EMNB guided samples. There was a weak correlation between the lesion size and the positive EMNB guided sampling (r: 0.34). Twenty-one of 29 (72%) patients with positive bronchus signs had positive EMNB guided samples, compared to 10/18 (56%) patients without bronchus signs; however, the difference was not statistically significant (p-value 0.335). When the presence or absence of rapid onsite examination of cytopathological specimens (ROSE) was compared during the procedure, a trend favoring the presence of ROSE could be seen, but this was statistically non-significant (p-value 0.078). In this series, one patient with pre-existing triple vessel coronary artery disease developed an inferior wall ST-segment elevation myocardial infarction (STEMI), likely secondary to spasm. This patient recovered completely and was discharged from the hospital.

Conclusion:

This study demonstrates that EMNB can be safely performed in a Middle Eastern population with results similar to those reported in major international studies. The highest diagnostic yield was in patients with a bronchus sign on a CT scan, and combining EMNB with ROSE can increase the chances of having a positive diagnostic bronchoscopy. However, patients and physicians need to be aware of the need to follow up with the patients with negative biopsies to ensure that false negatives are not missed.

A Direct Comparative Study of Bronchoscopic Navigation Planning Platforms for Peripheral Lung Navigation: The ATLAS Study

BACKGROUND

The use of mapping to guide peripheral lung navigation (PLN) represents an advance in the management of peripheral pulmonary lesions (PPL). Software has been developed to virtually reconstruct computed tomography images into 3-dimensional airway maps and generate navigation pathways to target PPL. Despite this there remain significant gaps in understanding the factors associated with navigation success and failure including the cartographic performance characteristics of these software algorithms. This study was designed to determine whether differences exist when comparing PLN mapping platforms.

METHODS

An observational direct comparison was performed to evaluate navigation planning software packages for the lung. The primary endpoint was distance from the terminal end of the virtual navigation pathway to the target PPL. Secondary endpoints included distal virtual and segmental airway generations built to the target and/or in each lung.

RESULTS

Twenty-five patient chest computed tomography scans with 41 PPL were evaluated. Virtual airway and navigation pathway maps were generated for each scan/nodule across all platforms. Virtual navigation pathway comparison revealed differences in the distance from the terminal end of the navigation pathway to the target PPL (robotic bronchoscopy 9.4 mm vs. tip-tracked electromagnetic navigation 14.2 mm vs. catheter based electromagnetic navigation 17.2 mm, P=0.0005) and in the generation of complete distal airway maps.

CONCLUSION

Comparing PLN planning software revealed significant differences in the generation of virtual airway and navigation maps. These differences may play an unrecognized role in the accurate PLN and biopsy of PPL. Further prospective trials are needed to quantify the effect of the differences reported.

A Novel Electromagnetic Navigation Bronchoscopy System for the Diagnosis of Peripheral Pulmonary Nodules: A Randomized Trial

RATIONALE

Endobronchial ultrasound (EBUS) combined with a guide sheath (GS) as an instrument for confirming the proximity of the bronchoscope and its relationship to the lesion can increase the diagnostic yield when conducting transbronchial lung biopsy of peripheral pulmonary nodules (PPNs). A novel electromagnetic navigational bronchoscopy (ENB) system comprising a thinner locatable sensor probe as a guidance instrument was developed to be suitable for a thin bronchoscope with a 2-mm-diameter working channel. The diagnostic efficacy of EBUS-GS with or without this ENB system has not been confirmed.

OBJECTIVES

To compare the diagnostic value and safety of EBUS-GS with or without ENB system for diagnosing PPNs.

METHODS

A prospective, multicenter, randomized controlled clinical trial was designed and conducted at 3 centers. Patients with PPNs suspected to be malignant were enrolled and randomly assigned to the ENB-EBUS-GS group or EBUS-GS group. The primary endpoint was the diagnostic yield in each group. The secondary endpoint was the procedural time and other factors affecting diagnostic yield. The safety endpoint was procedural complications.

RESULTS

Four hundred participants were enrolled from July 2018 to October 2019 and 385 patients were analyzed, with 193 in the ENB-EBUS-GS group and 192 in the EBUS-GS group. The mean nodule size was 21.7±5.3 mm. The diagnostic yields were 82.9% (95% confidence interval (CI), 77.6%-88.2%) in the ENB-EBUS-GS group and 73.4% (95% CI, 67.2%-79.7%) in the EBUS-GS group. The difference between the two groups was 9.5% (95% CI, 2.6%-16.3%), with an adjusted difference of 9.0% (95% CI, 2.3%-15.8%), after adjusting for the stratification factors and center. The time for finding lesions in the ENB-EBUS-GS was shorter than that in the EBUS-GS group (213.2±145.6s vs. 264.8±189.5s, p=0.003). And intraoperative hemorrhage occurred 3.6% in the ENB-EBUS-GS group and 3.1% in the EBUS-GS group, without significant differences between the two groups.

CONCLUSIONS

The novel ENB system combined with EBUS-GS demonstrated improved ability to locate PPNs, achieving a high diagnostic yield for PPNs compared to EBUS-GS alone in a safe and efficient procedure. Clinical trial registered with ClinicalTrials.gov (NCT03569306).

Update on Image-Guided Thermal Lung Ablation: Society Guidelines, Therapeutic Alternatives, and Postablation Imaging Findings

Percutaneous image-guided thermal ablation (IGTA) has been endorsed by multiple societies as a safe and effective lung-preserving treatment for primary lung cancer and metastases involving the lung and chest wall. This article reviews the role of IGTA in the care continuum of patients with thoracic neoplasms and discusses strategies to identify the optimal local therapy considering patient and tumor characteristics. The advantages and disadvantages of percutaneous thermal ablation compared to surgical resection and stereotactic body radiotherapy are summarized. Principles of radiofrequency ablation, microwave ablation, and cryoablation, as well as the emerging use of transbronchial thermal ablation, are described. Specific considerations are presented regarding the role of thermal ablation for early-stage non-small cell lung cancer (NSCLC), multifocal primary NSCLC, pulmonary metastases, salvage of recurrent NSCLC after surgery or radiation, and pain palliation for tumors involving the chest wall. Recent changes to professional society guidelines regarding the role of thermal ablation in the lung, including for treatment of oligometastatic disease, are highlighted. Finally, recommendations are provided for imaging follow-up after thermal ablation of lung tumors, accompanied by examples of expected postoperative findings and patterns of disease recurrence.

[Application and Progress of Electromagnetic Navigation Bronchoscopy in Department of Thoracic Surgery]

Lung cancer ranks the first cancer-related morbidity and mortality in China. With the development and penetration of imaging technology, increasing small pulmonary peripheral Nodules (SPPNs) have been detected. However, precise location and diagnosis of SPPNs is still a tough problem for clinical diagnosis and treatment in department of thoracic surgery. With the development of electromagnetic navigation bronchoscopy (ENB), it provides a novel minimally invasive method for the diagnosis and treatment of SPPNs. In this review, we summarized the application and progress of ENB in preoperative positioning, diagnosis, and local treatment, then, discussed the clinical application of ENB in the hybrid operating room.
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Microwave ablation via a flexible catheter for the treatment of nonsurgical peripheral lung cancer: A pilot study

Background

Endobronchial microwave ablation via flexible catheter offers the potential for local therapy for inoperable peripheral lung cancer. The study aimed to evaluate the feasibility and safety of navigation bronchoscopy‐guided water‐cooled microwave ablation catheter for nonsurgical peripheral lung cancer.

Methods

This was a prospective single arm pilot study. Patients with early stage or multiple primary peripheral lung cancer who were nonsurgical candidates for surgery were enrolled in the study. Bronchoscopic microwave ablation was performed via a flexible water‐cooled microwave ablation antenna under the guidance of navigation bronchoscopy. Radial probe endobronchial ultrasound combined with fluoroscopy was used to confirm the position. Treatment outcomes were evaluated based on follow‐up chest CT and positron emission tomography scans. Primary endpoints were technical success and safety. Secondary endpoints were complete ablation rate, 2‐year local control rate, and progression‐free survival.

Results

Thirteen patients were enrolled in the study from April 2018 to July 2019. A total of 19 sessions of microwave ablation were performed on 14 tumors under the guidance of navigation bronchoscopy. The technical success was 100%. Treatment‐related complications occurred in two patients. The complete ablation rate was 78.6% (11/14). The 2‐year local control rate was 71.4%. Median progression‐free survival was 33 months for all patients.

Conclusions

In this pilot study, bronchoscopic microwave ablation appears to be feasible with acceptable occurrence of complication in the treatment of peripheral lung cancer under the guidance of navigation bronchoscopy.

Shape-Sensing Robotic-Assisted Bronchoscopy in the Diagnosis of Pulmonary Parenchymal Lesions

BACKGROUND

The landscape of guided bronchoscopy for the sampling of pulmonary parenchymal lesions is evolving rapidly. Shape-sensing robotic-assisted bronchoscopy (ssRAB) recently was introduced as means to allow successful sampling of traditionally challenging lesions.

RESEARCH QUESTION

What are the feasibility, diagnostic yield, determinants of diagnostic sampling, and safety of ssRAB in patients with pulmonary lesions?

STUDY DESIGN AND METHODS

Data from 131 consecutive ssRAB procedures performed at a US-based cancer center between October 2019 and July 2020 were captured prospectively and analyzed retrospectively. Definitions of diagnostic procedures were based on prior standards. Associations of procedure- and lesion-related factors with diagnostic yield were examined by univariate and multivariate generalized linear mixed models.

RESULTS

A total of 159 pulmonary lesions were targeted during 131 ssRAB procedures. The median lesion size was 1.8 cm, 59.1% of lesions were in the upper lobe, and 66.7% of lesions were beyond a sixth-generation airway. The navigational success rate was 98.7%. The overall diagnostic yield was 81.7%. Lesion size of ≥ 1.8 cm and central location were associated significantly with a diagnostic procedure in the univariate analysis. In the multivariate model, lesions of ≥ 1.8 cm were more likely to be diagnostic compared with lesions < 1.8 cm, after adjusting for lung centrality (OR, 12.22; 95% CI, 1.66-90.10). The sensitivity and negative predictive value of ssRAB for primary thoracic malignancies were 79.8% and 72.4%, respectively. The overall complication rate was 3.0%, and the pneumothorax rate was 1.5%.

INTERPRETATION

This study was the first to provide comprehensive evidence regarding the usefulness and diagnostic yield of ssRAB in the sampling of pulmonary parenchymal lesions. ssRAB may represent a significant advancement in the ability to access and sample successfully traditionally challenging pulmonary lesions via the bronchoscopic approach, while maintaining a superb safety profile. Lesion size seems to remain the major predictor of a diagnostic procedure.

Single-Use and Reusable Flexible Bronchoscopes in Pulmonary and Critical Care Medicine

Flexible bronchoscopy plays a critical role in both diagnostic and therapeutic management of a variety of pulmonary disorders in the bronchoscopy suite and the intensive care unit. In the set-ting of the ongoing viral pandemic, single-use flexible bronchoscopes (SUFB) have garnered attention as various professional pulmonary societies have released guidelines regarding uses for SUFB given the concern for risk of viral transmission when using reusable flexible bronchoscopes (RFB). In addition to offering sterility, SUFBs are portable, easily accessible, and may be more cost-effective than RFB when considering the potential costs of treating bronchoscopy-related infections. Furthermore, since SUFBs are one time use, they do not require reprocessing after use, and therefore may translate to reduced cleaning and storage costs. Despite these advantages, RFBs are still routinely used to perform advanced diagnostic and therapeutic bronchoscopic procedures given the need for optimal maneuverability, handling, angle of deflection, image quality, and larger channel size for passing of ancillary instruments. Here, we review the published evidence on the applications of single-use and reusable bronchoscopes in bronchoscopy suites and intensive care units. Specifically, we will discuss the advantages and disadvantages of these devices as pertinent to fundamental, advanced, and therapeutic bronchoscopic interventions.

Preoperative electromagnetic navigation bronchoscopy-guided one-stage multiple-dye localization for resection of subsolid nodules: A single-center pilot study

Background

Electromagnetic navigation bronchoscopy (ENB)‐guided transbronchial dye marking and video‐assisted thoracoscopic surgery (VATS) is an emerging technique that enables successful resection of multiple small subsolid pulmonary nodules. The aim of this study was to evaluate the accuracy and safety of preoperative ENB‐guided transbronchial multiple dye localization for VATS resection of subsolid pulmonary nodules.

Methods

As a single‐center pilot study, we recruited patients with at least two small or subsolid pulmonary nodules. Multiple‐dye localization was performed by intraoperative ENB‐guided transbronchial injection of an indigo carmine dye. The patients underwent VATS for sublobar resection immediately after localization. The accuracy of ENB‐guided dye marking was checked.

Results

ENB‐guided one‐stage multiple dye localization was conducted for 18 pulmonary nodules in seven patients between September 2018 and December 2019. The mean diameter of the pulmonary nodules was 9.3 mm (range, 4–18) and the mean distance from the pleura to pulmonary nodule was 6 mm (range, 1–17 mm). ENB‐guided transbronchial multiple dye localization was successfully performed in 94.4% (17/18), and the accuracy of ENB‐guided dye marking was 88.2% (15/17). When two nodules were not seen in intraoperative fields, anatomical sublobar resection was performed. There was no conversion to thoracotomy and operative mortalities. Among the seven patients, only one patient showed mild intrabronchial bleeding but stopped spontaneously. The changes in lung function after multiple wedge resections (−1.6% to 24.8%) were tolerable level.

Conclusions

ENB‐guided one‐stage transbronchial dye localization showed accurate and safe intraoperative identification of multiple subsolid pulmonary nodules. A large scale prospective clinical study is warranted.

Percutaneous Electromagnetic Transthoracic Nodule Localization for Ground Glass Nodules

Background

A recent increase in the incidental detection of ground glass nodules (GGNs) has created a need for improved diagnostic accuracy in screening for malignancies. However, surgical diagnosis remains challenging, especially via video-assisted thoracoscopic surgery (VATS). Herein, we present the efficacy of a novel electrical navigation system for perioperative percutaneous transthoracic nodule localization.

Methods

Eighteen patients with GGNs who underwent electromagnetic navigated percutaneous transthoracic needle localization (ETTNL), followed by 1-stage diagnostic wedge resections via VATS between January and December 2020, were included in the analysis. Data on patient characteristics, nodules, procedures, and pathological diagnoses were collected and retrospectively reviewed.

Results

Of the 18 nodules, 17 were successfully localized. Nine nodules were pure GGNs, and the remaining 9 were part-solid GGNs. The median nodule size was 9.0 mm (range, 4.0-20.0 mm); and the median depth from the visceral pleura was 5.2 mm (range, 0.0-14.4 mm). The median procedure time was 10 minutes (range, 7-20 minutes). The final pathologic results showed benign lesions in 3 cases and malignant lesions in 15 cases.

Conclusion

Perioperative ETTNL appears to be an effective method for the localization of GGNs, providing guidance for a 1-stage VATS procedure.

A Review of Robotic-Assisted Bronchoscopy Platforms in the Sampling of Peripheral Pulmonary Lesions

Robotic-assisted bronchoscopy is one of the newest additions to clinicians’ armamentarium for the biopsy of peripheral pulmonary lesions in light of the suboptimal yields and sensitivities of conventional bronchoscopic platforms. In this article, we review the existing literature pertaining to the feasibility as well as sensitivity of available robotic-assisted bronchoscopic platforms.

Is Methionyl-tRNA Synthetase Applicable as a Diagnostic Marker for Lung Cancer in Bronchial Ultrasound-Guided Brushing Cells?

BACKGROUND AND OBJECTIVE

Methionyl-tRNA synthetase (MARS) and A variant of Aminoacyl-tRNA synthetase interacting multifunctional protein 2 (AIMP2) with an exon 2 deletion (AIMP2-DX2) are known to be overexpressed in lung cancer. However, their role as diagnostic markers in lung cancer has not been well established. Thus, we evaluated their diagnostic performance in brushed cells obtained from nodular lung lesions suspected of lung cancer.

METHODS

Samples obtained by radial endobronchial ultrasound-guided brushing were processed for cytological examination with Papanicolaou (Pap) staining. Then, double IF staining with MARS and AIMP2-DX2 antibodies was measured in the cytology samples for peripheral lung nodules. The diagnostic performance was compared against biomarkers.

RESULTS

MARS IF staining was the only independent staining method used for the prediction of malignant cells. The area under the curve (AUC) of conventional cytology, MARS IF, and MARS IF plus cytology was 0.64, 0.68, and 0.69, respectively. The diagnostic accuracy was increased in MARS IF plus conventional cytology compared with cytology alone (71% vs. 47%).

CONCLUSIONS

The combination of MARS staining with conventional cytology showed increases in the diagnostic accuracy for diagnosing lung nodules suspected of lung cancer on chest-computed tomography scans.

Visually Navigated Bronchoscopy using three cycle-Consistent generative adversarial network for depth estimation

[Background] Electromagnetically Navigated Bronchoscopy (ENB) is currently the state-of-the art diagnostic and interventional bronchoscopy. CT-to-body divergence is a critical hurdle in ENB, causing navigation error and ultimately limiting the clinical efficacy of diagnosis and treatment. In this study, Visually Navigated Bronchoscopy (VNB) is proposed to address the aforementioned issue of CT-to-body divergence. [Materials and Methods] We extended and validated an unsupervised learning method to generate a depth map directly from bronchoscopic images using a Three Cycle-Consistent Generative Adversarial Network (3cGAN) and registering the depth map to preprocedural CTs. We tested the working hypothesis that the proposed VNB can be integrated to the navigated bronchoscopic system based on 3D Slicer, and accurately register bronchoscopic images to pre-procedural CTs to navigate transbronchial biopsies. The quantitative metrics to asses the hypothesis we set was Absolute Tracking Error (ATE) of the tracking and the Target Registration Error (TRE) of the total navigation system. We validated our method on phantoms produced from the pre-procedural CTs of five patients who underwent ENB and on two ex-vivo pig lung specimens. [Results] The ATE using 3cGAN was 6.2 +/- 2.9 [mm]. The ATE of 3cGAN was statistically significantly lower than that of cGAN, particularly in the trachea and lobar bronchus (p < 0.001). The TRE of the proposed method had a range of 11.7 to 40.5 [mm]. The TRE computed by 3cGAN was statistically significantly smaller than those computed by cGAN in two of the five cases enrolled (p < 0.05). [Conclusion] VNB, using 3cGAN to generate the depth maps was technically and clinically feasible. While the accuracy of tracking by cGAN was acceptable, the TRE warrants further investigation and improvement.

Electromagnetic navigation-guided preoperative localization: the learning curve analysis

Background

The electromagnetic navigation bronchoscopy (ENB) was increasingly used to mark small pulmonary nodules (PNs) for video-assisted thoracic surgery (VATS) resection due to high effectiveness and low risk. However, no study reports the learning curve of ENB-guided preoperative localization. In the study, we aimed to describe the learning curve of ENB-guided preoperative PNs localization initially.

Methods

Consecutive PNs cases that underwent ENB localizations between October 2018 and October 2019 by the same surgeon in our center were included in the study. The cumulative sum (CUSUM) method was used to analyze the learning curve of ENB localization.

Results

A total of 89 ENB localization from 64 patients were included in this study. The learning curve was divided into 3 phases: Phase I (the initial 11 cases), Phase II (the 12th to the 47th cases), and Phase III (the 47th to the 89th cases). The success rate of ENB localization has increased with the accumulation of operational experience in 3 phases (72.73%, 91.67%, and 97.62%, P=0.049). The distance from the ENB guide wire tip to the center of the lesion in Phase I was significantly longer than those in Phase II and Phase III (2.46±1.76 vs. 1.36±0.94 and 1.47±0.97 cm, P=0.014 and 0.027, respectively). Sex, bronchus sign, and learning curve phase were independent risk factors influencing operative time (OT) (OR =8.187, 18.847, and 13.920, respectively).

Conclusions

The technical competency, which is indicated by higher success rate, localization accuracy, and shorter OT, for ENB-guided preoperative PNs localization was achieved at the 47th operation.

Depth-based branching level estimation for bronchoscopic navigation

PURPOSE

Bronchoscopists rely on navigation systems during bronchoscopy to reduce the risk of getting lost in the complex bronchial tree-like structure and the homogeneous bronchus lumens. We propose a patient-specific branching level estimation method for bronchoscopic navigation because it is vital to identify the branches being examined in the bronchus tree during examination.

METHODS

We estimate the branching level by integrating the changes in the number of bronchial orifices and the camera motions among the frames. We extract the bronchial orifice regions from a depth image, which is generated using a cycle generative adversarial network (CycleGAN) from real bronchoscopic images. We calculate the number of orifice regions using the vertical and horizontal projection profiles of the depth images and obtain the camera-moving direction using the feature point-based camera motion estimation. The changes in the number of bronchial orifices are combined with the camera-moving direction to estimate the branching level.

RESULTS

We used three in vivo and one phantom case to train the CycleGAN model and four in vivo cases to validate the proposed method. We manually created the ground truth of the branching level. The experimental results showed that the proposed method can estimate the branching level with an average accuracy of 87.6%. The processing time per frame was about 61 ms.

CONCLUSION

Experimental results show that it is feasible to estimate the branching level using the number of bronchial orifices and camera-motion estimation from real bronchoscopic images.

Multi-Dimensional Display of Wang's Lymph Node Map Using Virtual Bronchoscopic Navigation System

Background: Transbronchial needle aspiration (TBNA) is a classical technique for diagnosing mediastinal-hilar lymph node enlargement. However, the diagnostic value of conventional TBNA (cTBNA) is limited in small lymph nodes.

Methods: Here, we generated an innovative multi-dimensional virtual lymph node map on top of Wang’s lymph node map using a Lungpoint Virtual Bronchoscopic Navigation System.

Results: The virtual bronchoscopic navigation (VBN) system was combined with computed tomography (CT) images to generate extrabronchial, endobronchial, sagittal, coronal as well as horizontal views of the 11 intrathoracic lymph node stations and their adjacent tissues and blood vessels. We displayed the specific puncture site of each lymph node station. The 11 stations were divided into four groups: right mediastinal stations, left mediastinal stations, central mediastinal stations and hilar stations.

Conclusion: The VBN system provides a precise view of the intrabronchial landmarks, which may increase the diagnostic accuracy of intrathoracic lymph node adenopathy and assist bronchoscopists with practicing TBNA.

Radial endobronchial ultrasound-assisted transbronchial needle aspiration for pulmonary peripheral lesions in the segmental bronchi adjacent to the central airway

Background

Tissue samples from lesions located in the 3rd to 5th segmental bronchi are challenging to obtain. In this retrospective study, we aimed to evaluate the diagnostic rate of pulmonary peripheral lesions located in the 3rd to 5th segmental bronchi, near the inner field of lung on the computed tomography (CT) image and outside the bronchus, using radial endobronchial ultrasound (REBUS) followed by transbronchial needle aspiration (TBNA).

Methods

This retrospective study enrolled patients whose preoperative CT examinations showed a lesion located in the segmental bronchi (3rd to 5th), yet adjacent to the inner field of lung on the CT image. REBUS followed by TBNA was used to acquire tissue samples from these lesions. A bronchoscope was used to reach the bronchi surrounding the lesion, and an ultrasound probe was used to determine the lesion's location. Then, the ultrasound probe was withdrawn, and puncture was performed at the location that was determined by ultrasound. The tissue specimens obtained were subjected to pathological examination.

Results

Nineteen patients were enrolled in this study including 15 males and 4 females with an average age of 55 years old. Of the enrollees, 8 patients (42.1%) were successfully diagnosed with samples obtained through TBNA, including 6 cases of lung cancer, 1 case of non-specific inflammation, and 1 case of cryptococcal infection. The diagnostic rate was 42.1%. No post-procedural complications were observed among the patients. There was no significant difference in nodule diameter between patients with a diagnostic sample and those in whom TBNA failed to provide a diagnosis (2.99±0.96 vs. 2.26±1.27 cm, P=0.20).

Conclusions

With the assistance of REBUS, TBNA can acquire sufficient samples to achieve a reasonably diagnostic rate for parenchymal lung lesions located near the inner field of lung on the CT image without intrabronchial invasion.

Robotic bronchoscopy for peripheral pulmonary lesions: a convergence of technologies

PURPOSE OF REVIEW

Robotic bronchoscopy is the newest advanced diagnostic bronchoscopy technology for biopsying peripheral pulmonary lesions; sensitivity for malignancy is currently suboptimal using modalities, such as radial endobronchial ultrasound or electromagnetic navigational bronchoscopy. We review the pitfalls of prior methods and the technological advancements with robotic bronchoscopy.

RECENT FINDINGS

The contributors to reduced diagnostic sensitivity with current approaches include limitations in: navigation to the target, confirmation once the target is reached, and tissue acquisition. CT to body divergence with virtual reality methods, such as with electromagnetic navigation, potential false-positive confirmation with radial endobronchial ultrasound because of intraprocedural induced atelectasis, and lack of bronchoscopic and instrument maneuverability are all limitations to improving sensitivity. Robotic bronchoscopy enhances navigation through target pathway selection, allows for further reach in the distal airways, and improves tissue acquisition with more flexible and maneuverable biopsy instruments but lacks a high-fidelity target confirmation system.

SUMMARY

Robotic bronchoscopy shows promise in biopsying peripheral lesions. Current published studies focus on diagnostic yield with robotic bronchoscopy. Future studies with long-term follow-up will be needed to assess diagnostic sensitivity for lung cancer and if robotic bronchoscopy is superior to other advanced diagnostic bronchoscopic techniques for peripheral pulmonary lesions.

Invasive modalities for the diagnosis of peripheral lung nodules

INTRODUCTION

Lung nodules are being increasingly discovered either incidentally or through lung cancer screening chest CT scans. Some of these will turn out to be malignant and therefore it is important to obtain an accurate and timely diagnosis of lung cancer when suspected.

AREAS COVERED

This review will cover various invasive diagnostic modalities available to sample lung nodules. Data from key studies, obtained from PubMed searches, will be reviewed. Emerging technologies such as cone-beam CT and robotic-assisted bronchoscopies will be discussed along with ddata available currently to support their use.

EXPERT OPINION

The best approach to diagnosing a lung nodule - whether found incidentally or because of lung cancer screening - is continuously evolving. While CT-guided lung nodule biopsy has a high diagnostic yield, the risk of pneumothorax is often a concern. Bronchoscopy has a better safety profile, but diagnostic ability falls short of CT-guided biopsy. Existing technologies such as electromagnetic navigation have not demonstrated a high diagnostic yield. Factors responsible for this relatively lower low diagnostic yield will be discussed in detail. Emerging technologies such as cone-beam CT scan and robotic bronchoscopy have addressed some of these issues and initial experience has demonstrated better diagnostic yield.

Efficacy and Safety of Cone-Beam Computed Tomography-Derived Augmented Fluoroscopy Combined with Endobronchial Ultrasound in Peripheral Pulmonary Lesions

BACKGROUND

The diagnostic yield of peripheral pulmonary lesions (PPLs) using radial endobronchial ultrasound (EBUS) remains challenging without navigation systems. Cone-beam computed tomography-derived augmented fluoroscopy (CBCT-AF) represents a recently developed technique, and its clinical utility remains to be investigated.

OBJECTIVES

The aim of this study was to investigate the diagnostic yield of transbronchial biopsy (TBB) using a combination of CBCT-AF and radial EBUS.

METHODS

We recruited consecutive patients with PPLs who underwent radial EBUS-guided TBB, with or without AF, between October 2018 and July 2019. Following propensity score 1:1 matching, we recorded the procedure-related data and measured their efficacy and safety.

RESULTS

While 72 patients received EBUS-plus-AF, 235 patients received EBUS only. We included 53 paired patients following propensity score matching. The median size of lesions was 2.8 and 2.9 cm in the EBUS-plus-AF group and EBUS-only group, respectively. Diagnostic yield was higher in the former group (75.5 vs. 52.8%; p = 0.015). The diagnostic yield for the EBUS-plus-AF group was significantly higher for lesions ≤30 mm (73.5 vs. 36.1%; p = 0.002). Moreover, there was no significant difference in the complication rates (3.8 vs. 5.7%; p = 1.000). Twenty-four nodules (45.3%) were invisible by fluoroscopy in the EBUS-plus-AF group. All of them were identifiable on CBCT images and successfully annotated for AF. The mean radiation dose of total procedure, CBCT, and fluoroscopy was 19.59, 16.4, and 3.17 Gy cm2, respectively.

CONCLUSIONS

TBB using a combination of CBCT-AF and EBUS resulted in a satisfactory diagnostic yield and safety.

Lesion characteristics affecting yield of electromagnetic navigational bronchoscopy

RATIONALE

Electromagnetic navigational bronchoscopy (ENB) is an important, minimally invasive diagnostic tool for malignant and benign peripheral lung lesions, offering lower complication risks than transthoracic needle aspirations. As a relatively new technology, the best sampling modality and lesion characteristics for ENB has yet to be determined. We evaluated the sensitivity and diagnostic yield of different sampling modalities (needle aspiration, brush biopsy, transbronchial forceps biopsies) and radiographical lesion characteristics by Tsuboi classification. We also evaluated the difference in yield and sensitivity with the addition of radial probe EBUS to augment ENB.

METHODS

We completed a retrospective chart review of all patients that had ENB performed at our institution since its implementation in 2011. We reviewed the lesion size, location, Tsuboi classification, cytology, pathology results and analyzed biopsy specimen tool types.

RESULTS

We included a total of 248 patients who had ENB performed between 2011 and 2018. Average age was 67 years and 50% female. A total of 270 lesions were targeted with a mean size of 24 ± 12 mm. Sensitivity for malignancy was 59.2% with a diagnostic yield of 72.3%. Sensitivity and diagnostic accuracy trended higher with combined sampling modalities (brush and transbronchial needle aspiration and forcep biopsy). Lesions with type I and type II Tsuboi classification of bronchus sign had higher sensitivity compared to type III classification (67.9% [n = 101 type I], 64.6% [n = 65 type II], 37.9% [n = 36 type III]), p = 0.01 and p = 0.04.

CONCLUSION

For navigation bronchoscopy, sensitivity is higher in bronchus sign lesions that end directly into lesion (Tsuboi type I) and travel through malignant lesions (Tsuboi type II) compared to tangentially circumventing the lesion (Tsuboi type III).

Recent Trends of Lung Cancer in Korea

Lung cancer is one of the leading causes of cancer-related deaths in Korea. Although the smoking rate has decreased over time, the prevalence of lung cancer still remains high. In this study, we reviewed recent trends on the incidence, epidemiology, screening, diagnosis, and treatment of lung cancer in Korea by analyzing data from the national lung cancer registry and recently-published studies. Although approximately 40% of patients with non-small cell lung cancer (NSCLC) were diagnosed as stage IV, the 5-year relative survival rate improved from 11.3% (1993-1995) to 30.2% (2013-2017), possibly due to advances in methods of diagnosis and therapy. In addition, the 2019 implementation of the national lung cancer screening program with low-dose computed tomography may have also contributed to these improvements in survival rates. Recently, molecular diagnosis has become more widely used in the identification of genetic mutations in tissue specimens. Target therapy and immune checkpoint inhibitors have also been successfully used, particularly in cases of advanced NSCLC. In the future, further research on the optimal management of lung cancer remains necessary.

Robotic-Assisted Navigation Bronchoscopy as a Paradigm Shift in Peripheral Lung Access

INTRODUCTION

The sensitivity of suspicious lung nodules biopsied by currently available techniques is suboptimal. Robotic-assisted navigation bronchoscopy (RANB) is a novel method for biopsying lung nodules. Our study objective was to determine the sensitivity for malignancy and overall diagnostic accuracy for RANB when combined with cone beam CT (CBCT) for secondary confirmation.

METHODS

52 consecutive patients were prospectively enrolled. Demographic data, nodule characteristics, procedural information, and follow-up results were obtained.

RESULTS

Mean patient age was 66, with the majority Caucasian (73%) females (65%) with a similar number of never (46%) and former (46%) smokers. 15 patients had a history of cancer and 3 had a prior thoracic surgery. 59 total nodules were included as 7 patients had two nodules biopsied. Mean nodule diameter was < 2 cm in all dimension with the majority solid (41, 70%) and located in the upper lobes (left: 22, 37%; right: 17, 29%). Bronchus sign was absent (32, 54%) or present (27, 46%) in a similar number. All nodules were successfully reached with nine (15%) requiring minor directional changes after initial cone beam CT. A tissue diagnosis was obtained in 83% (49/59) of biopsied nodules, with malignancy (31, 65%) most common. Including all biopsy results and follow-up imaging, we obtained an 84% (31/37) procedural sensitivity for malignancy and an overall 86% (51/59) diagnostic yield.

CONCLUSION

RANB with CBCT increases sensitivity for malignancy and diagnostic accuracy of lung nodule biopsies. Combining these modalities has the potential to shift the diagnostic approach to pulmonary nodules.

Diagnostic Value of Virtual Bronchoscopic Navigation Combined With Endobronchial Ultrasound Guided Transbronchial Lung Biopsy for Peripheral Pulmonary Lesions

Objective:

X-ray guided transbronchial ultrasound-guided transbronchial lung biopsy (EBUS-TBLB) can improve the diagnostic yield of peripheral pulmonary lesions (PPLs), but it needs special requirements. The purpose of this study was to investigate the clinical value of virtual bronchoscopy navigation (VBN) combined with EBUS-TBLB in the diagnosis of PPLs without X-ray guidance.

Methods:

The 105 patients with PPLs underwent EBUS-TBLB with or without VBN randomly. The diagnostic yield, the operation time and complications were evaluated in the 2 groups.

Results:

No significant difference was found between the VBN+EBUS group and the EBUS group (76.0% vs. 65.5%, P = 0.287). The operation time of VBN+EBUS group was significantly shorter than that of EBUS group (20.6 ± 12.8 min vs. 28.6 ± 14.3 min, P = 0.023). No severe procedure related complications occurred.

Conclusions:

VBN can shorten the operation time. The combination of VBN and EBUS-TBLB is a safe and effective diagnosis technique for PPLs.

Diagnostic yield of electromagnetic navigational bronchoscopy: A safety net community-based hospital experience in the United States

INTRODUCTION:

Electromagnetic navigational bronchoscopy (ENB) is an excellent tool to diagnose peripheral pulmonary nodules, especially in the setting of emphysema and pulmonary fibrosis. However, most of these procedures are done by interventional pulmonologists and academic tertiary centers under general anesthesia. Studies evaluating the diagnostic utility of this tool in safety-net community hospitals by pulmonologists not formally trained in this technology are lacking. The objective was to evaluate the diagnostic yield of ENB done in such a setting and its associated complications.

METHODS:

Retrospective chart review of consecutive ENB procedures over 5 years from 2014, since its inception in our institution-a safety-net community based hospital was performed. Multiple variables were analyzed to assess their impact on diagnostic yields.

RESULTS:

After exclusion criteria were applied, 72 patients with 76 procedures were eventually included within our study, with an overall 1-year diagnostic yield of 80.2%. Sensitivity for malignancy was 73% and negative predictive value of 65%. Primary lung cancer was the most common diagnosis obtained, followed by tuberculosis (TB). The overall complication rates were low, with only 1 patient (1.3%) requiring hospitalization due to pneumothorax needing tube thoracostomy. No deaths or respiratory failures were noted within the cohort. The only significant variable affecting diagnostic yield was forced expiratory volume in 1 s. The presence of emphysema did not affect diagnostic yield.

CONCLUSIONS:

ENB is safe and feasible with a high diagnostic success rate even when performed by pulmonologists not formally trained in interventional pulmonology in low resource settings under moderate sedation.

Electromagnetic navigation bronchoscopy as an adjunct diagnostic tool in the Danish lung cancer diagnostic pathway: an initial retrospective single centre series

Background

The performance of electromagnetic navigation bronchoscopy (ENB) is reported with substantial variation, which may question its clinical usefulness. However, ENB may hold its true value when used as an additional minimal invasive diagnostic option before potential surgery in selected diagnostically challenging patients where traditional diagnostic methods have failed. We evaluated the safety and performance of ENB when used as an adjunct diagnostic tool in the Danish lung cancer diagnostic pathway (DLCDP) and its ability to reduce surgical diagnostic procedures.

Methods

A retrospective study was performed on eighty-two consecutive patients at Odense University Hospital from June 2016 to March 2018 with diagnostically challenging pulmonary lesions referred for ENB as an adjunct diagnostic procedure under the DLCDP. Patients with benign or inconclusive ENB pathology were either referred for further biopsies, surgery or repeated computer tomography (CT) scans for surveillance purposes.

Results

Eighty-one ENB procedures were performed in 80 patients. In 87.7% of the cases previous diagnostic methods had been unsuccessful. The mean target diameter was 1.55 cm and the average follow-up duration was 11 months. The diagnostic accuracy was 75%, while the diagnostic yield/sensitivity, negative predictive value and negative likelihood ratio was 51%, 67% and 0.49, respectively. No pneumothoraces and only one intrapulmonary haemorrhage was recorded, which was managed conservatively. The learning curve revealed an increase in diagnostic accuracy from 67.5% to 82.9% when comparing the first 40 ENB procedures with the last 41 procedures, however, this was not statistically significant (p-value: 0.11).

Conclusions

ENB was found to be a safe procedure with an acceptable diagnostic accuracy and yield in highly selected diagnostically challenging patients. The introduction of ENB carried a notable learning curve but proved to be a valuable adjunct diagnostic option in the DLCDP, which may help to reduce the number of potentially unnecessary or harmful surgical procedures in frail patients.

State of the Art: Robotic Bronchoscopy

Increased detection of lung nodules has led to trying to improve technologies for localization and/or tissue acquisition. Previous bronchoscopic techniques have limitations that have led to further advancements in technology. Robotic bronchoscopy has emerged as new technology for the localization, diagnosis, and potential treatment of lung nodules. The robotic bronchoscopic platform was developed to improve peripheral reach of lung nodules, provide direct continuous visualization of the periphery, and offer more precise control of the instrumentation. We review the progression of bronchoscopy, evolution to the robotic platform and its early outcomes, with considerations for future advancements.