Study Design and Rationale: A Multicenter, Prospective Trial of Electromagnetic Bronchoscopic and Electromagnetic Transthoracic Navigational Approaches for the Biopsy of Peripheral Pulmonary Nodules (ALL IN ONE Trial)

Navigational Bronchoscopy versus Computed Tomography-guided Transthoracic Needle Biopsy for the Diagnosis of Indeterminate Lung Nodules: protocol and rationale for the VERITAS multicenter randomized trial

Background

Lung nodule incidence is increasing. Many nodules require biopsy to discriminate between benign and malignant etiologies. The gold-standard for minimally invasive biopsy, computed tomography-guided transthoracic needle biopsy (CT-TTNB), has never been directly compared to navigational bronchoscopy, a modality which has recently seen rapid technological innovation and is associated with improving diagnostic yield and lower complication rate. Current estimates of the diagnostic utility of both modalities are based largely on non-comparative data with significant risk for selection, referral, and publication biases.

Methods

The VERITAS trial (na V igation E ndoscopy to R each Indeterminate lung nodules versus T ransthoracic needle A spiration, a randomized controlled S tudy) is a multicenter, 1:1 randomized, parallel-group trial designed to ascertain whether electromagnetic navigational bronchoscopy with integrated digital tomosynthesis is noninferior to CT-TTNB for the diagnosis of peripheral lung nodules 10-30 mm in diameter with pre-test probability of malignancy of at least 10%. The primary endpoint is diagnostic accuracy through 12 months follow-up. Secondary endpoints include diagnostic yield, complication rate, procedure duration, need for additional invasive diagnostic procedures, and radiation exposure.

Discussion

The results of this rigorously designed trial will provide high-quality data regarding the management of lung nodules, a common clinical entity which often represents the earliest and most treatable stage of lung cancer. Several design challenges are described. Notably, all nodules are centrally reviewed by an independent interventional pulmonology and radiology adjudication panel relying on pre-specified exclusions to ensure enrolled nodules are amenable to sampling by both modalities while simultaneously protecting against selection bias favoring either modality. Conservative diagnostic yield and accuracy definitions with pre-specified criteria for what non-malignant findings may be considered diagnostic were chosen to avoid inflation of estimates of diagnostic utility.

Trial registration

ClinicalTrials.gov NCT04250194.

CT-Guided vs. Navigational Bronchoscopic Biopsies for Solitary Pulmonary Nodules: A Single-Institution Retrospective Comparison

OBJECTIVE

Lung cancer is the second most common cause of death by cancer. Multiple modalities can be used to obtain a tissue sample from a pulmonary nodule. We aimed to compare the yield and adverse events related to transthoracic needle aspiration (TTNA) and Electromagnetic Navigation Biopsy (ENB) at our institution.

METHODS

This was a single-center retrospective study in which all patients referred for evaluation of a pulmonary lesion over 5 years (1 January 2013 to 31 December 2018) were identified. Our primary outcome was to compare the accuracy of TTNA to that of ENB in establishing the diagnosis of pulmonary lesions. Secondary outcomes included the evaluation of the adverse events and the sensitivity, specificity, positive, and negative predictive value of each modality.

RESULTS

A total of 1006 patients were analyzed. The mean age of patients in the TTNA and the ENB group was 67.2 ± 11.2 years and 68.3 ± 9.2 years respectively. Local anesthesia was predominantly used for TTNA and moderate sedation was more commonly used in the ENB group. We found ENB to have an accuracy of 57.1%, with a sensitivity of 40.0%, a specificity of 100.0%, a positive predictive value of 100.0%, and a negative predictive value of 40.0%. As for the TTNA, the accuracy was 75.9%, with a sensitivity of 77.5%, a specificity of 61.5%, a positive predictive value of 95.0%, and a negative predictive value of 22.5%. The rate of clinically significant complications was higher in the TTNA group (8.2%) as compared to the ENB group (4.7%) with a p-value < 0.001.

CONCLUSION

TTNA was superior to ENB-guided biopsy for the diagnostic evaluation of lung nodules. However, the complication rate was much higher in the TTNA group as compared to the ENB group.

A Multicenter, Single-Arm, Prospective Trial Assessing the Diagnostic Yield of Electromagnetic Bronchoscopic and Transthoracic Navigation for Peripheral Pulmonary Nodules

Rationale: Strict adherence to procedural protocols and diagnostic definitions is critical to understand the efficacy of new technologies. Electromagnetic navigational bronchoscopy (ENB) for lung nodule biopsy has been used for decades without a solid understanding of its efficacy, but offers the opportunity for simultaneous tissue acquisition via electromagnetic navigational transthoracic biopsy (EMN-TTNA) and staging via endobronchial ultrasound (EBUS). Objective: To evaluate the diagnostic yield of EBUS, ENB, and EMN-TTNA during a single procedure using a strict a priori definition of diagnostic yield with central pathology adjudication. Methods: A prospective, single-arm trial was conducted at eight centers enrolling participants with pulmonary nodules (<3 cm; without computed tomography [CT]- and/or positron emission tomography-positive mediastinal lymph nodes) who underwent a staged procedure with same-day CT, EBUS, ENB, and EMN-TTNA. The procedure was staged such that, when a diagnosis had been achieved via rapid on-site pathologic evaluation, the procedure was ended and subsequent biopsy modalities were not attempted. A study finding was diagnostic if an independent pathology core laboratory confirmed malignancy or a definitive benign finding. The primary endpoint was the diagnostic yield of the combination of CT, EBUS, ENB, and EMN-TTNA. Measurements and Main Results: A total of 160 participants at 8 centers with a mean nodule size of 18 ± 6 mm were enrolled. The diagnostic yield of the combined procedure was 59% (94 of 160; 95% confidence interval [CI], 51-66%). Nodule regression was found on same-day CT in 2.5% of cases (4 of 160; 95% CI, 0.69-6.3%), and EBUS confirmed malignancy in 7.1% of cases (11 of 156; 95% CI, 3.6-12%). The yield of ENB alone was 49% (74 of 150; 95% CI, 41-58%), that of EMN-TTNA alone was 27% (8 of 30; 95% CI, 12-46%), and that of ENB plus EMN-TTNA was 53% (79 of 150; 95% CI, 44-61%). Complications included a pneumothorax rate of 10% and a 2% bleeding rate. When EMN-TTNA was performed, the pneumothorax rate was 30%. Conclusions: The diagnostic yield for ENB is 49%, which increases to 59% with the addition of same-day CT, EBUS, and EMN-TTNA, lower than in prior reports in the literature. The high complication rate and low diagnostic yield of EMN-TTNA does not support its routine use. Clinical trial registered with www.clinicaltrials.gov (NCT03338049).

Predicting reachability to peripheral lesions in transbronchial biopsies using CT-derived geometrical attributes of the bronchial route

PURPOSE

The bronchoscopist's ability to locate the lesion with the bronchoscope is critical for a transbronchial biopsy. However, much less study has been done on the transbronchial biopsy route. This study aims to determine whether the geometrical attributes of the bronchial route can predict the difficulty of reaching tumors in bronchoscopic intervention.

METHODS

This study included patients who underwent bronchoscopic diagnosis of lung tumors using electromagnetic navigation. The biopsy instrument was considered "reached" and recorded as such if the tip of the tracked bronchoscope or extended working channel was in the tumors. Four geometrical indices were defined: Local curvature (LC), plane rotation (PR), radius, and global relative angle. A Mann-Whitney U test and logistic regression analysis were performed to analyze the difference in geometrical indices between the reachable and unreachable groups. Receiver operating characteristic analysis (ROC) was performed to evaluate the geometrical indices to predict reachability.

RESULTS

Of the 41 patients enrolled in the study, 16 patients were assigned to the unreachable group and 25 patients to the reachable group. LC, PR, and radius have significantly higher values in unreachable cases than in reachable cases ([Formula: see text], [Formula: see text], [Formula: see text]). The logistic regression analysis showed that LC and PR were significantly associated with reachability ([Formula: see text], [Formula: see text]). The areas under the curve with ROC analysis of the LC and PR index were 0.903 and 0.618. The LC's cut-off value was 578.25.

CONCLUSION

We investigated whether the geometrical attributes of the bronchial route to the lesion can predict the difficulty of reaching the lesions in the bronchoscopic biopsy. LC, PR, and radius have significantly higher values in unreachable cases than in reachable cases. LC and PR index can be potentially used to predict the navigational success of the bronchoscope.

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.

Advances in Diagnostic Bronchoscopy

The increase in incidental discovery of pulmonary nodules has led to more urgent requirement of tissue diagnosis. The peripheral pulmonary nodules are especially challenging for clinicians. There are various modalities for diagnosis and tissue sampling of pulmonary lesions, but most of these modalities have their own limitations. This has led to the development of many advanced technical modalities, which have empowered pulmonologists to reach the periphery of the lung safely and effectively. These techniques include thin/ultrathin bronchoscopes, radial probe endobronchial ultrasound (RP-EBUS), and navigation bronchoscopy—including virtual navigation bronchoscopy (VNB) and electromagnetic navigation bronchoscopy (ENB). Recently, newer technologies—including robotic-assisted bronchoscopy (RAB), cone-beam CT (CBCT), and augmented fluoroscopy (AF)—have been introduced to aid in the navigation to peripheral pulmonary nodules. Technological advances will also enable more precise tissue sampling of smaller peripheral lung nodules for local ablative and other therapies of peripheral lung cancers in the future. However, we still need to overcome the CT-to-body divergence, among other limitations. In this review, our aim is to summarize the recent advances in diagnostic bronchoscopy technology.

Anesthesia considerations to reduce motion and atelectasis during advanced guided bronchoscopy

Partnership between anesthesia providers and proceduralists is essential to ensure patient safety and optimize outcomes. A renewed importance of this axiom has emerged in advanced bronchoscopy and interventional pulmonology. While anesthesia-induced atelectasis is common, it is not typically clinically significant. Advanced guided bronchoscopic biopsy is an exception in which anesthesia protocols substantially impact outcomes. Procedure success depends on careful ventilation to avoid excessive motion, reduce distortion causing computed tomography (CT)-to-body-divergence, stabilize dependent areas, and optimize breath-hold maneuvers to prevent atelectasis. Herein are anesthesia recommendations during guided bronchoscopy. An FiO₂ of 0.6 to 0.8 is recommended for pre-oxygenation, maintained at the lowest tolerable level for the entire the procedure. Expeditious intubation (not rapid-sequence) with a larger endotracheal tube and non-depolarizing muscle relaxants are preferred. Positive end-expiratory pressure (PEEP) of up to 10-12 cm H₂O and increased tidal volumes help to maintain optimal lung inflation, if tolerated by the patient as determined during recruitment. A breath-hold is required to reduce motion artifact during intraprocedural imaging (e.g., cone-beam CT, digital tomosynthesis), timed at the end of a normal tidal breath (peak inspiration) and held until pressures equilibrate and the imaging cycle is complete. Use of the adjustable pressure-limiting valve is critical to maintain the desired PEEP and reduce movement during breath-hold maneuvers. These measures will reduce atelectasis and CT-to-body divergence, minimize motion artifact, and provide clearer, more accurate images during guided bronchoscopy. Following these recommendations will facilitate a successful lung biopsy, potentially accelerating the time to treatment by avoiding additional biopsies. Application of these methods should be at the discretion of the anesthesiologist and the proceduralist; best medical judgement should be used in all cases to ensure the safety of the patient.

Electromagnetic Navigation Bronchoscopy With Tomosynthesis-based Visualization and Positional Correction: Three-dimensional Accuracy as Confirmed by Cone-Beam Computed Tomography

BACKGROUND

Electromagnetic navigation bronchoscopy (ENB) aids in lung lesion biopsy. However, anatomic divergence between the preprocedural computed tomography (CT) and the actual bronchial anatomy during the procedure can limit localization accuracy. An advanced ENB system has been designed to mitigate CT-to-body divergence using a tomosynthesis-based software algorithm that enhances nodule visibility and allows for intraprocedural local registration.

MATERIALS AND METHODS

A prospective, 2-center study was conducted in subjects with single peripheral lung lesions ≥10 mm to assess localization accuracy of the superDimension navigation system with fluoroscopic navigation technology. Three-dimensional accuracy was confirmed by cone-beam computed tomography. Complications were assessed through 7 days.

RESULTS

Fifty subjects were enrolled (25 per site). Lesions were <20 mm in 61.2% (30/49). A bronchus sign was present in 53.1% (26/49). Local registration was completed in 95.9% (47/49). Three-dimensional target overlap (primary endpoint) was achieved in 59.6% (28/47) and 83.0% (39/47) before and after location correction, respectively. Excluding subjects with unevaluable video files, target overlap was achieved 68.3% (28/41) and 95.1% (39/41), respectively. Malignant results were obtained in 53.1% (26/49) by rapid on-site evaluation and 61.2% (30/49) by final pathology of the ENB-aided sample. Diagnostic yield was not evaluated. Procedure-related complications were pneumothorax in 1 subject (no chest tube required) and scant hemoptysis in 3 subjects (no interventions required).

CONCLUSION

ENB with tomosynthesis-based fluoroscopic navigation improved the 3-dimensional convergence between the virtual target and actual lung lesion as confirmed by cone-beam computed tomography. Future studies are necessary to understand the impact of this technology on diagnostic yield.

Transthoracic Needle Biopsy: How to Maximize Diagnostic Accuracy and Minimize Complications

Although transthoracic needle biopsy (TTNB) was introduced for lung biopsy about 40 years ago, it is still mainstay of pathologic diagnosis in lung cancer, because it is relatively inexpensive and can obtain tissue regardless of the tumor-bronchus relationship. With several technological advances, proceduralists can perform TTNB more safely and accurately. Utilizing ultrasound-guided biopsy for peripheral lesions in contact with the pleura and rapid on-site evaluation during the procedure are expected to make up the weakness of TTNB. However, due to the inherent limitations of the percutaneous approach, the incidence of complications such as pneumothorax or bleeding is inevitably higher than that of other lung biopsy techniques. Thorough understating of each biopsy modality and additional technique are fundamental for maximizing diagnostic accuracy and minimizing the complications.

Recent developments in advanced diagnostic bronchoscopy

The field of bronchoscopy is advancing rapidly. Minimally invasive diagnostic approaches are replacing more aggressive surgical ones for the diagnosis and staging of lung cancer. Evolving diagnostic modalities allow early detection and serve as an adjunct to early treatment, ideally influencing patient outcomes. In this review, we will elaborate on recent bronchoscopic developments as well as some promising investigational tools and approaches in development. We aim to offer a concise overview of the significant advances in the field of advanced bronchoscopy and to put them into clinical context. We will also address potential complications and current diagnostic challenges associated with sampling central and peripheral lung lesions.

Recent Advances in Interventional Pulmonology

The field of interventional pulmonology has grown rapidly since first being defined as a subspecialty of pulmonary and critical care medicine in 2001. The interventional pulmonologist has expertise in minimally invasive diagnostic and therapeutic procedures involving airways, lungs, and pleura. In this review, we describe recent advances in the field as well as up-and-coming developments, chiefly from the perspective of medical practice in the United States. Recent advances include standardization of formalized training, new tools for the diagnosis and potential treatment of peripheral lung nodules (including but not limited to robotic bronchoscopy), increasingly well-defined bronchoscopic approaches to management of obstructive lung diseases, and minimally invasive techniques for maximizing patient-centered outcomes for those with malignant pleural effusion.

Evaluating the efficacy of bronchoscopy for the diagnosis of early stage lung cancer

Novel diagnostic techniques for lung cancer are rapidly evolving. Specifically, several novel changes to bronchoscopy are reaching clinical evaluation. It is critical to think about historical standards for evaluating new diagnostic testing, and put those concepts into the framework of lung cancer. Often a thorough evaluation of new technology is not performed as a part of regulatory marketing clearance. Therefore, we must consider how to best study novel testing beyond these regulatory minimums. There are several methodological principles that can achieve this goal such as using a control arm, more thorough reporting of enrolled patients, consecutive patient enrollment, and adequate sample size. We hope clinicians, particularly those performing bronchoscopy for lung nodules, will feel empowered to critically appraise the evaluation of new diagnostic testing for lung cancer moving forward.

Navigational bronchoscopy: a guide through history, current use, and developing technology

The peripheral pulmonary nodule offers unique challenges to the clinician, especially in regards to diagnostic approach. Quite often the etiology of the nodule is spurious, though the specter of malignancy drives accurate classification of the nodule. Diagnostic approaches range in degrees of invasiveness, accuracy, and morbidity. Bronchoscopic access to these nodules had been plagued by low reported yields, especially in fluoroscopically invisible nodules. Navigational bronchoscopy, however, allowed more accurate access to peripheral nodules while maintaining a low morbidity, and thus reshaped the historic diagnostic algorithms. Though navigational bronchoscopy was initially associated with electromagnetic navigation, newer approaches to navigation and new technologies provide enthusiasm that yield can improve. In this article we will provide a historical approach to navigational bronchoscopy, from its origins to its current state, and we will discuss developing technology and its potential role in the evolving paradigm of the peripheral nodule biopsy.

Virtual or reality: divergence between preprocedural computed tomography scans and lung anatomy during guided bronchoscopy

Guided bronchoscopy offers a minimally invasive and safe method for accessing indeterminate pulmonary nodules. However, all current guided bronchoscopy systems rely on a preprocedural computed tomography (CT) scan to create a virtual map of the patient's airways. Changes in lung anatomy between the preprocedural CT scan and the bronchoscopy procedure can lead to a divergence between the expected and actual location of the target lesion. Termed "CT-to-body divergence", this effect reduces diagnostic yield, adds time to the procedure, and can be challenging for the operator. The objective of this paper is to describe the concept of CT-to-body divergence, its contributing factors, and methods and technologies that might minimize its deleterious effects on diagnostic yield.

Safety and diagnostic performance of pulmonologists performing electromagnetic guided percutaneous lung biopsy (SPiNperc)

BACKGROUND AND OBJECTIVE

Percutaneous lung biopsy for diagnostic sampling of peripheral lung nodules has been widely performed by interventional radiologists under computed tomography (CT) guidance. New technology allows pulmonologists to perform percutaneous lung biopsies using electromagnetic (EM) guided technology. With the adoption of this new technique, the safety, feasibility and diagnostic yield need to be explored. The goal of this study was to determine the safety, feasibility and diagnostic yield of EM-guided percutaneous lung biopsy performed by pulmonologists.

METHODS

We conducted a retrospective, multicentre study of 129 EM-guided percutaneous lung biopsies that occurred between November 2013 and March 2017. The study consisted of seven academic and three community medical centres.

RESULTS

The average age of participants was 65.6 years, BMI was 26.3 and 50.4% were females. The majority of lesions were in the right upper lobe (37.2%) and left upper lobe (31.8%). The mean size of the lesions was 27.31 mm and the average distance from the pleura was 13.2 mm. Practitioners averaged two fine-needle aspirates and five core biopsies per procedure. There were 23 (17.8%) pneumothoraces, of which 16 (12.4%) received small-bore chest tube placement. The diagnostic yield of percutaneous lung biopsy was 73.7%. When EM-guided bronchoscopic sampling was also performed during the same procedural encounter, the overall diagnostic yield increased to 81.1%.

CONCLUSION

In this large multicentred series, the use of EM guidance for percutaneous lung biopsies was safe and feasible, with acceptable diagnostic yield in the hands of pulmonologists. A prospective multicentre trial to validate these findings is currently underway (NCT03338049).