Cone beam computed tomography-guided thin/ultrathin bronchoscopy for diagnosis of peripheral lung nodules: a prospective pilot study

The diagnostic performance and optimal strategy of cone beam CT-assisted bronchoscopy for peripheral pulmonary lesions: A systematic review and meta-analysis

Cone-beam computed tomography (CBCT) assisted bronchoscopy shows prospective advantages in diagnosing peripheral pulmonary lesions (PPLs), but its diagnostic value and potential influencing factors remain unclear. What is the clinical value and optimal strategy of CBCT-assisted bronchoscopy in diagnosing PPLs? The references were searched from PubMed, EmBase, and Web of Science. Studies reporting diagnostic yield and potential influencing factors of CBCT-assisted bronchoscopy were included. The navigational success rate, diagnostic rate, complication rate, and potential influencing factors were pooled by random-effects model and meta-regression. A total of 1,441 patients with 1,540 lesions from 15 studies were included in our meta-analysis. The pooled navigational success rate (97.0% vs 81.6%; odds ratio [OR] 5.12) and diagnostic rate (78.5% vs 55.7%; OR 2.51) of the CBCT-assisted group were significantly higher than those without CBCT. The complication rate of CBCT-assisted bronchoscopy was 4.4% (95%CI: 0.02-0.07). Cone-beam CT combined with r-EBUS can achieve the highest diagnostic rate. Applying positive end-expiratory pressure could improve the diagnostic rate and reduce the complication rate (p < 0.05). Lesions located in the upper lobe could achieve a higher diagnostic rate and lesions located in the right lobes could get a lower complication rate (p < 0.05). Cone-beam CT combined with r-EBUS seems to be the effective and optimal approach to ameliorate the navigation success rate and diagnostic rate of diagnosing PPLs.Clinical trial registration: This study was registered in PROSPERO (Registration Number: CRD42022378992). URL: PROSPERO (york.ac.uk).

Radiation in the Bronchoscopy Suite: One Center's Experience With Navigational Bronchoscopy and a Review of the Literature

BACKGROUND

This study aimed to quantify radiation doses during navigational bronchoscopy procedures, comparing them with reported cohorts and evaluating the LungVision (Body Vision Medical Inc.) system's efficacy in dose reduction.

METHODS

This retrospective observational study included 52 consecutive navigational bronchoscopy cases, categorized into 4 imaging groups based on the C-arm: Cios Spin (Siemens Healthineers), or OEC 9900 (GE HealthCare); and the 3D tomographic imaging algorithm: Cios Spin's onboard imaging, or LungVision's AI-driven imaging. Patient and lesion data, outcomes, and radiation indices were collected. Existing literature on 3D image guidance for bronchoscopic lung nodules was reviewed to compare reported radiation doses.

RESULTS

Combining LungVision with Cios Spin significantly reduced radiation dose in all cases compared with using Cios Spin alone: Cumulative air kerma (Ka,r) reduced from 238.7 to 119.1 mGy (P=0.03), and air kerma-area product (KAP) decreased from 28.19 to 15.09 Gy·cm2 (P=0.03). For biopsy cases, LungVision led to notable dose reductions: Ka,r of 279 to 129.1 mGy, and KAP of 30.70 to 16.27 Gy·cm2. LungVision notably reduced radiation indices in 7 paired spins, isolating the 3D imaging algorithm as the sole variable with the same Cios Spin C-arm. A literature review provides additional context on radiation for bronchoscopic biopsies.

CONCLUSION

Following the "as low as reasonably achievable" (ALARA) principle minimizes ionizing radiation exposure, benefiting patients and operators. Physicians should compare baseline radiation levels with the literature and adopt dose-reduction techniques. LungVision's lower dose indices render it effective for real-time 3D imaging during navigational bronchoscopy while reducing radiation dose.

Efficacy and safety of cone-beam computed tomography-guided bronchoscopy for peripheral pulmonary lesions: a systematic review and meta-analysis

Background

Cone-beam computed tomography (CBCT)-guided bronchoscopy is increasingly utilized for diagnosing peripheral pulmonary lesions (PPLs). We carried out the meta-analysis for assessing the efficacy and safety of CBCT-guided bronchoscopy for PPLs.

Methods

An extensive search in several databases was conducted to identify relevant articles. We evaluated the quality of studies with the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. The pooled diagnostic yield (DY) and adverse event rate with the 95% confidence interval (CI) were computed. Subgroup analyses were performed according to additional use of navigation, use of radial endobronchial ultrasound (rEBUS), use of fixed or mobile CBCT, whether computed tomography (CT) spin was performed before biopsy to affirm tool-in-lesion, use of rapid onsite cytologic examination (ROSE), strictness of the definition of DY, and study design. Further analysis was performed to explore the association between odds of diagnosis with CBCT guided bronchoscopy and PPLs characteristics (>20 vs. ≤20 mm, non-upper lobe vs. upper lobe, with bronchus sign vs. without bronchus sign, and solid vs. non-solid) as well as sampling methods (forceps vs. fine needle aspiration, forceps vs. cryoprobe sampling). The pooled odds ratio (OR) and 95% CI were calculated. The significance level was set at 0.05. All analyses were performed by using meta package in R version 4.3.2.

Results

We included 23 studies involving 1,769 patients and 1,863 PPLs in the meta-analysis. The overall pooled DY of CBCT-guided bronchoscopy was 80.2% (95% CI: 76.0-84.1%). Subgroup analysis showed that the DY was highest when CBCT was used with robotic-assisted navigation bronchoscopy (pooled DY 87.5%; 95% CI: 81.5-92.4%), the DY was 78.9% (95% CI: 70.8-85.9%) when CBCT was used alone without other navigation techniques. Lesion size >20 mm, presence of bronchus sign and solid lesions were associated with significant increase in the odds of diagnosis with CBCT-guided bronchoscopy. Pooled adverse event rate was 2.3% (95% CI: 1.2-3.6%).

Conclusions

CBCT-guided bronchoscopy is a safe technique with high DY in diagnosing PPLs.

Transbronchial Needle Aspiration via Ultrathin Bronchoscope Improves Diagnostic Yield for Peripheral Lung Lesions: Randomized Sequencing Trial

BACKGROUND

Peripheral pulmonary lesions (PPLs) are frequently identified and require diagnostic sampling. Diagnostic yield of radial endobronchial ultrasound (rEBUS) guided bronchoscopic biopsies is suboptimal, despite ultrasound confirmation of navigation success. Pairing ultrathin bronchoscopy and peripheral transbronchial needle aspiration (pTBNA) may improve yield.

METHODS

We prospectively recruited consecutive patients undergoing Olympus MP190F ultrathin bronchoscopy with rEBUS-guided sampling of PPLs. Cases were randomized to pTBNA (Olympus Periview FLEX) either before or after the usual transbronchial forceps biopsy (TBLBx) and brush. Diagnostic yield from cytology or histopathology, clinical outcomes to a minimum 24 months follow-up and complications were recorded.

RESULTS

One hundred one sampled lesions were included (pTBNA first 61, pTBNA last 40). Overall diagnostic yield was 66.3%, with no significant difference between groups (64% vs. 70% P=0.528) or prespecified subgroups according to sampling order. Seventy lesions had an end diagnosis of malignancy, of which 50 were correctly diagnosed (71.4%). TBLBx (49/96, 49%) and pTBNA (48/101, 47.5%) had the highest individual positive yield. For 12 (11.9%) participants, pTBNA was the only positive sample. Lesions <20 mm and those with eccentric rEBUS image seemed to benefit most from this approach. Rapid on-site cytologic examination (ROSE) was associated with both positive procedural diagnosis (P=0.019) and pTBNA-positive samples (P=0.004). Pneumothorax occurred in 4% and moderate bleeding in 5%. Thirteen percent had an unplanned admission within 1 month of bronchoscopy.

CONCLUSION

Adding pTBNA to conventional sampling through an ultrathin bronchoscope guided by rEBUS, improved diagnostic yield (11.9% additional diagnoses). The sampling sequence did not affect the yield of pTBNA.

Peripheral pulmonary lesion: novel approaches in endoscopic guidance systems and a state-of-the-art review

Diagnosis of peripheral pulmonary lesion (PPL) is the most challenging field in bronchoscopy and interventional pulmonology, which concerns early lung cancer diagnosis. Despite novel techniques and new approaches to the periphery of the lung, almost 25% of PPLs remain undiagnosed. Bronchoscopy with guide systems, virtual and/or electromagnetic navigation, robotic bronchoscopy, and transparenchymal nodule approaches tend to provide a higher percentage of reaching the lesion, but the diagnostic yield rarely exceeds 75%, regardless of the instruments used. Further studies are needed to evaluate what the main constraints of this discrepancy are and if a combined use of these techniques and instruments can provide an increased diagnostic yield.

Fluoroscopy and Cone Beam CT Guidance in Robotic Interventions

Developments in robotic interventions have greatly affected the field of interventional radiology (IR), particularly when combined with imaging modalities such as fluoroscopy and cone-beam computed tomography (CBCT). The aim of this review is to compare and evaluate the safety, precision, and clinical outcomes of fluoroscopy and CBCT-guided robotic interventions in IR. An extensive search of the literature on PubMed and Google Scholar databases was conducted up to November 2024. Searched terms included "robotic interventions," "fluoroscopy guidance," "cone-beam CT guidance," and "robotic surgery." Literature review showed improved patient outcomes in robotic-assisted procedures, with fewer complications and higher success rates especially in anatomically challenging cases. Fluoroscopy-guided robotic interventions provide real-time imaging, allowing for accurate interventions while CBCT-guided procedures offer enhanced 3D visualization, reducing radiation exposure while maintaining high diagnostic accuracy and shorter needle puncture times. Both fluoroscopy and CBCT-guided robotic interventions play a critical role in advancing interventional radiology and are expected to improve procedural outcomes in IR.

Investigating 4D respiratory cone-beam CT imaging for thoracic interventions on robotic C-arm systems: a deformable phantom study

Increasingly, interventional thoracic workflows utilize cone-beam CT (CBCT) to improve navigational and diagnostic yield. Here, we investigate the feasibility of implementing free-breathing 4D respiratory CBCT for motion mitigated imaging in patients unable to perform a breath-hold or without suspending mechanical ventilation during thoracic interventions. Circular 4D respiratory CBCT imaging trajectories were implemented on a clinical robotic CBCT system using additional real-time control hardware. The circular trajectories consisted of 1 × 360° circle at 0° tilt with fixed gantry velocities of 2°/s, 10°/s, and 20°/s. The imaging target was an in-house developed anthropomorphic breathing thorax phantom with deformable lungs and 3D-printed imaging targets. The phantom was programmed to reproduce 3 patient-measured breathing traces. Following image acquisition, projections were retrospectively binned into ten respiratory phases and reconstructed using filtered back projection, model-based, and iterative motion compensated algorithms. A conventional circular acquisition on the system of the free-breathing phantom was used as comparator. Edge Response Width (ERW) of the imaging target boundaries and Contrast-to-Noise Ratio (CNR) were used for image quality quantification. All acquisitions across all traces considered displayed visual evidence of motion blurring, and this was reflected in the quantitative measurements. Additionally, all the 4D respiratory acquisitions displayed a lower contrast compared to the conventional acquisitions for all three traces considered. Overall, the current implementation of 4D respiratory CBCT explored in this study with various gantry velocities combined with motion compensated algorithms improved image sharpness for the slower gantry rotations considered (2°/s and 10°/s) compared to conventional acquisitions over a variety of patient traces.

Shape-sensing Robotic-assisted Bronchoscopy (SS-RAB) in Sampling Peripheral Pulmonary Nodules: A Prospective, Multicenter Clinical Feasibility Study in China

BACKGROUND

The ION system is a shape-sensing robotic-assisted bronchoscopy (SS-RAB) platform developed to biopsy peripheral pulmonary nodules (PPNs). There is a lack of data describing the use of this system in the Chinese population. The study aimed to assess the feasibility and safety of using SS-RAB to diagnose PPNs across multiple centers within China.

METHODS

This prospective, multicenter study used SS-RAB in consecutive patients with solid or sub-solid PPNs 8 to 30 mm in largest diameter. Primary endpoints were diagnostic yield and the rates of procedure- or device-related complications. Radial endobronchial ultrasound (rEBUS) was to confirm lesion localization, followed by sampling, using the Flexision biopsy needle, biopsy forceps, and cytology brush. Subjects with nonmalignant index biopsy results were followed up to 6 months.

RESULTS

A total of 90 PPNs were biopsied from 90 subjects across 3 centers using SS-RAB. The median nodule size was 19.4 mm (IQR: 19.3, 24.6) in the largest dimension. In all (100%) cases, the catheter successfully reached the target nodule with tissue samples obtained. The diagnostic yield was 87.8% with a sensitivity for malignancy of 87.7% (71/81). In a univariate analysis, nodule lobar location, presence of bronchus sign, and rEBUS view were associated with a diagnostic sample, but only rEBUS view showed an association in a multivariate analysis. The overall pneumothorax rate was 1.1% without pneumothorax requiring intervention, and there was no periprocedural bleeding.

CONCLUSION

As an emerging technology in the Chinese population, SS-RAB can safely biopsy PPNs with strong diagnostic performance.

Ultrathin Bronchoscopy Without Virtual Navigation for Diagnosis of Peripheral Lung Lesions

BACKGROUND

The increasing incidence of encountering lung nodules necessitates an ongoing search for improved diagnostic procedures. Various bronchoscopic technologies have been introduced or are in development, but further studies are needed to define a method that fits best in clinical practice and health care systems.

RESEARCH QUESTION

How do basic bronchoscopic tools including a combination of thin (outer diameter 4.2 mm) and ultrathin bronchoscopes (outer diameter 3.0 mm), radial endobronchial ultrasound (rEBUS) and fluoroscopy perform in peripheral pulmonary lesion diagnosis?

STUDY DESIGN AND METHODS

This is a retrospective review of the performance of peripheral bronchoscopy using thin and ultrathin bronchoscopy with rEBUS and 2D fluoroscopy without a navigational system for evaluating peripheral lung lesions in a single academic medical center from 11/2015 to 1/2021. We used a strict definition for diagnostic yield and assessed the impact of different variables on diagnostic yield, specifically after employment of the ultrathin bronchoscope. Logistic regression models were employed to assess the independent associations of the most impactful variables.

RESULTS

A total of 322 patients were included in this study. The median of the long axis diameter was 2.2 cm and the median distance of the center of the lesion from the visceral pleural surface was 1.9 cm. Overall diagnostic yield was 81.3% after employment of the ultrathin bronchoscope, with more detection of concentric rEBUS views (93% vs. 78%, p < 0.001). Sensitivity for detecting malignancy also increased from 60.5% to 74.7% (p = 0.033) after incorporating the ultrathin scope into practice, while bronchus sign and peripheral location of the lesion were not found to affect diagnostic yield. Concentric rEBUS view, solid appearance, upper/middle lobe location and larger size of the nodules were found to be independent predictors of successful achievement of diagnosis at bronchoscopy.

INTERPRETATION

This study demonstrates a high diagnostic yield of biopsy of lung lesions achieved by utilization of thin and ultrathin bronchoscopes. Direct visualization of small peripheral airways with simultaneous rEBUS confirmation increased localization rate of small lesions in a conventional bronchoscopy setting without virtual navigational planning.

Cone-beam computed tomography-guided shape-sensing robotic bronchoscopy vs. electromagnetic navigation bronchoscopy for pulmonary nodules

Background

Electromagnetic navigation bronchoscopy (ENB) and shape-sensing robotic-assisted bronchoscopy (ssRAB) are minimally invasive technologies for the diagnosis of pulmonary nodules. Cone-beam computed tomography (CBCT) has shown to increase diagnostic yield by allowing real-time confirmation of position of lesion and biopsy tool. There is a lack of comparative studies of such platforms using CBCT guidance to overcome computed tomography to body divergence. The aim of this study was to compare the diagnostic yield of ENB- and ssRAB-guided CBCT for biopsy of pulmonary nodules.

Methods

We conducted a retrospective comparative study of consecutive patients undergoing ENB-CBCT and ssRAB-CBCT. Navigational success was defined as biopsy tool within lesion confirmed during CBCT. Diagnostic yield was assessed using two methods: (I) presence of malignancy or benign histological findings that lead to a specific diagnosis at the time of bronchoscopy, and (II) longitudinal follow-up of patients with nonspecific benign finding during bronchoscopy.

Results

ENB-CBCT was used to biopsy 97 nodules and ssRAB-CBCT was used to biopsy 111 nodules. Median size of the lesion for the ENB-CBCT group was 16.5 mm [interquartile range (IQR), 12-22 mm] as compared to 12 mm (IQR, 9-16 mm) in the ssRAB-CBCT group (P<0.001). Navigational success was 70.1% in ENB-CBCT arm as compared to 83% in ssRAB-CBCT arm respectively (P=0.03). Diagnostic yield was 66% for ENB-CBCT and 89.2% for ssRAB-CBCT (P<0.001) following bronchoscopy; 79.4% for ENB-CBCT and 95.4% for ssRAB-CBCT (P<0.001) with longitudinal follow-up data respectively. Following multivariate regression analysis adjusting for the size of the lesion, distance from the pleura, presence of bronchus sign, number of CBCT spins, and number of nodules, the odds ratio for the diagnostic yield was 4.72 [95% confidence interval (CI): 2.05-10.85; P<0.001] in the ssRAB-CBCT group as compared with ENB-CBCT. The overall rate of adverse events was similar in both groups (P=0.77).

Conclusions

ssRAB-CBCT showed increased navigational success and diagnostic yield as compared to ENB-CBCT for pulmonary nodule biopsies.

Cone Beam Computed Tomography-Guided Navigation Bronchoscopy with Augmented Fluoroscopy for the Diagnosis of Peripheral Pulmonary Nodules: A Step-by-Step Guide

INTRODUCTION

Cone beam computed tomography-guided navigation bronchoscopy (CBCT-NB) with augmented fluoroscopy (AF) guidance represents a minimally invasive endobronchial technique for diagnosing small, peripheral pulmonary lesions. This approach is characterized by its high diagnostic accuracy and low complication risk. Current pilot trials are exploring the application of localized therapies using this innovative approach. This report aims to provide a detailed procedural guide for performing CBCT-NB with AF guidance as the only tool for navigation and image guided biopsy.

METHODS

We outline the procedural steps involved in the CBCT-NB procedure for diagnosing peripheral pulmonary lesions, supported by specific intra-procedural clinical video footage. The steps include (1) preprocedural considerations, (2) a detailed procedural workflow encompassing navigation to the target lesion, (3) position confirmation and tissue acquisition, and (4) postprocedural follow-up.

CONCLUSION

CBCT-NB with AF guidance is a safe and precise stand-alone navigation modality that offers high-resolution real-time 3D imaging, enhancing the diagnosis and potential treatment of peripheral pulmonary nodules.

INTRODUCTION

Cone beam computed tomography-guided navigation bronchoscopy (CBCT-NB) with augmented fluoroscopy (AF) guidance represents a minimally invasive endobronchial technique for diagnosing small, peripheral pulmonary lesions. This approach is characterized by its high diagnostic accuracy and low complication risk. Current pilot trials are exploring the application of localized therapies using this innovative approach. This report aims to provide a detailed procedural guide for performing CBCT-NB with AF guidance as the only tool for navigation and image guided biopsy.

METHODS

We outline the procedural steps involved in the CBCT-NB procedure for diagnosing peripheral pulmonary lesions, supported by specific intra-procedural clinical video footage. The steps include (1) preprocedural considerations, (2) a detailed procedural workflow encompassing navigation to the target lesion, (3) position confirmation and tissue acquisition, and (4) postprocedural follow-up.

CONCLUSION

CBCT-NB with AF guidance is a safe and precise stand-alone navigation modality that offers high-resolution real-time 3D imaging, enhancing the diagnosis and potential treatment of peripheral pulmonary nodules.

Improving Shape-Sensing Robotic-Assisted Bronchoscopy Outcomes with Mobile Cone-Beam Computed Tomography Guidance

BACKGROUND

Computed tomography to body divergence (CTBD) is one of the main barriers to bronchoscopic techniques for the diagnosis of peripherally located lung nodules. Cone-beam CT (CBCT) guidance is being rapidly adopted to correct for this phenomenon and to potentially increase diagnostic outcomes. In this trial, we hypothesized that the addition of mobile CBCT (m-CBCT) could improve the rate of tool in lesion (TIL) and the diagnostic yield of shape-sensing robotic-assisted bronchoscopy (SS-RAB).

METHODS

This was a prospective, single-arm study, which enrolled patients with peripheral lung nodules of 1-3 cm and compared the rate of TIL and the diagnostic yield of SS-RAB alone and combined with mCBCT.

RESULTS

A total of 67 subjects were enrolled, the median nodule size was 1.7 cm (range, 0.9-3 cm). TIL was achieved in 23 patients (34.3%) with SS-RAB alone, and 66 patients (98.6%) with the addition of mCBCT (p < 0.0001). The diagnostic yield of SS-RAB alone was 29.9% (95% CI, 29.3-42.3%) and it was 86.6% (95% CI, 76-93.7%) with the addition of mCBCT (p < 0.0001). There were no pneumothoraxes or any bronchoscopy-related complications, and the median total dose-area product (DAP) was 50.5 Gy-cm2.

CONCLUSIONS

The addition of mCBCT guidance to SS-RAB allows bronchoscopists to compensate for CTBD, leading to an increase in TIL and diagnostic yield, with acceptable radiation exposure.

Determinants of radiation exposure during mobile cone-beam CT-guided robotic-assisted bronchoscopy

BACKGROUND AND OBJECTIVE

Robotic-assisted bronchoscopy (RAB) is an emerging modality to sample pulmonary lesions. Cone-beam computed tomography (CBCT) can be incorporated into RAB. We investigated the magnitude and predictors of patient and staff radiation exposure during mobile CBCT-guided shape-sensing RAB.

METHODS

Patient radiation dose was estimated by cumulative dose area product (cDAP) and cumulative reference air kerma (cRAK). Staff equivalent dose was calculated based on isokerma maps and a phantom simulation. Patient, lesion and procedure-related factors associated with higher radiation doses were identified by logistic regression models.

RESULTS

A total of 198 RAB cases were included in the analysis. The median patient cDAP and cRAK were 10.86 Gy cm2 (IQR: 4.62-20.84) and 76.20 mGy (IQR: 38.96-148.38), respectively. Among staff members, the bronchoscopist was exposed to the highest median equivalent dose of 1.48 μSv (IQR: 0.85-2.69). Both patient and staff radiation doses increased with the number of CBCT spins and targeted lesions (p < 0.001 for all comparisons). Patient obesity, negative bronchus sign, lesion size <2.0 cm and inadequate sampling by on-site evaluation were associated with a higher patient dose, while patient obesity and inadequate sampling by on-site evaluation were associated with a higher bronchoscopist equivalent dose.

CONCLUSION

The magnitude of patient and staff radiation exposure during CBCT-RAB is aligned with safety thresholds recommended by regulatory authorities. Factors associated with a higher radiation exposure during CBCT-RAB can be identified pre-operatively and solicit procedural optimization by reinforcing radiation protective measures. Future studies are needed to confirm these findings across multiple institutions and practices.

Pulmonary Cytopathology: Current and Future Impact on Patient Care

Small biopsies of lung are routinely obtained by many methods, including several that result in cytologic specimens. Because lung cancer is often diagnosed at a stage for which primary resection is not an option, it is critical that all diagnostic, predictive, and prognostic information be derived from such small biopsy specimens. As the number of available diagnostic and predictive markers expands, cytopathologists must familiarize themselves with current requirements for specimen acquisition, handling, results reporting, and molecular and other ancillary testing, all of which are reviewed here.

Improving diagnostic strategies in bronchoscopy for peripheral pulmonary lesions

INTRODUCTION

In the past two decades, bronchoscopy of peripheral pulmonary lesions (PPLs) has improved its diagnostic yield due to the combination of various instruments and devices. Meanwhile, the application is complex and intertwined.

AREAS COVERED

This review article outlines strategies in diagnostic bronchoscopy for PPLs. We summarize the utility and evidence of key instruments and devices based on the results of clinical trials. Future perspectives of bronchoscopy for PPLs are also discussed.

EXPERT OPINION

The accuracy of reaching PPLs by bronchoscopy has improved significantly with the introduction of combined instruments such as navigation, radial endobronchial ultrasound, digital tomosynthesis, and cone-beam computed tomography. It has been accelerated with the advent of approach tools such as newer ultrathin bronchoscopes and robotic-assisted bronchoscopy. In addition, needle aspiration and cryobiopsy provide further diagnostic opportunities beyond forceps biopsy. Rapid on-site evaluation may also play an important role in decision making during the procedures. As a result, the diagnostic yield of bronchoscopy for PPLs has improved to a level comparable to that of transthoracic needle biopsy. The techniques and technologies developed in the diagnosis will be carried over to the next step in the transbronchial treatment of PPLs in the future.

Radiation Principles, Protection, and Reporting for Interventional Pulmonology: A World Association of Bronchology and Interventional Pulmonology White Paper

The use and availability of diverse advanced X-ray based imaging and guidance systems in the field of interventional pulmonology are rapidly growing. This popularity links inextricably to an increase in ionizing radiation use. Knowing ionizing radiation is hazardous, knowledge and competent use of X-ray imaging and guidance systems are important. The globally implemented As Low As Reasonably Achievable (ALARA) principle demands careful attention to minimize radiation exposure while achieving the precise goals of the intervention and imaging therein. To allow careful and targeted weighing of risk against reward while using X-ray based equipment, proper background knowledge of physics as well as imaging system aspects are needed. This white paper summarizes the principles of ionizing radiation which are crucial to enhance awareness and interpretation of dosimetric quantities. Consecutively, a consensus on standards for reporting radiation exposure in interventional pulmonology procedures is indicated to facilitate comparisons between different systems, approaches and results. Last but not least, it provides a list of practical measures, considerations and tips to optimize procedural imaging as well as reduce radiation dose to patients and staff.

Feasibility of a Prototype Image Reconstruction Algorithm for Motion Correction in Interventional Cone-Beam CT Scans

RATIONALE AND OBJECTIVES

Assess the feasibility of a prototype image reconstruction algorithm in correcting motion artifacts in cone-beam computed tomography (CBCT) scans of interventional instruments in the lung.

MATERIALS AND METHODS

First, phantom experiments were performed to assess the algorithm, using the Xsight lung phantom with custom inserts containing straight or curved catheters. During scanning, the inserts moved in a continuous sinusoidal or breath-hold mimicking pattern, with varying amplitudes and frequencies. Subsequently, the algorithm was applied to CBCT data from navigation bronchoscopy procedures. The algorithm's performance was assessed quantitatively via edge-sharpness measurements and qualitatively by three specialists.

RESULTS

In the phantom study, the algorithm improved sharpness in 13 out of 14 continuous sinusoidal motion and five out of seven breath-hold mimicking scans, with more significant effects at larger motion amplitudes. Analysis of 27 clinical scans showed that the motion corrected reconstructions had significantly sharper edges than standard reconstructions (2.81 (2.24-6.46) vs. 2.80 (2.16-4.75), p = 0.003). These results were consistent with the qualitative assessment, which showed higher scores in the sharpness of bronchoscope-tissue interface and catheter-tissue interface in the motion-corrected reconstructions. However, the tumor demarcation ratings were inconsistent between raters, and the overall image quality of the new reconstructions was rated lower.

CONCLUSION

Our findings suggest that applying the new prototype algorithm for motion correction in CBCT images is feasible. The algorithm improved the sharpness of medical instruments in CBCT scans obtained during diagnostic navigation bronchoscopy procedures, which was demonstrated both quantitatively and qualitatively.

Shape-Sensing Robotic-Assisted Bronchoscopy in the Multiple Pulmonary Nodule Diagnosis during a Single Anesthetic Event

INTRODUCTION

The widespread use of computed tomography as a screening tool for early lung cancer has increased detection of pulmonary lesions. It is common to encounter patients with more than one peripheral pulmonary nodule (PPN) of uncertain etiology. Shape-sensing robotic-assisted bronchoscopy (ssRAB) emerges as a potential alternative to biopsy multiple PPN, in addition to mediastinal staging in single anesthetic procedure.

METHODS

This is a single-center, retrospective review of 22 patients who underwent ssRAB for evaluation of two or more PPN, between November 2021 and April 2023 at Mayo Clinic, FL, USA.

RESULTS

A total of 46 PPNs were biopsied in 22 patients. All lesions were ≤2 cm with a median minimum and maximum cross-sectional lesion size of 1.40 cm and 1.05 cm, respectively. Diagnostic yield was 86.9% (n = 40), and target reach was 91.3% (n = 42). Most lesions were in the upper lobes, a solid pattern was found in 78.3% (n = 36), bronchus sign was present in 82.6% of cases (n = 38), 54.4% (n = 25) were malignant nodules, and 32.6% (n = 15) were benign. Fourteen patients had at least one malignant lesion out of two or more nodules sampled, and 10 patients had a malignant diagnosis for all sampled lesions. The complication rate was 9% (n = 2) with one case of bleeding and one of pneumothorax.

CONCLUSION

This study is, to our knowledge, the first to assess the use and safety of ssRAB for diagnosis of multiple PPN in a single anesthetic event. This procedure will mainly impact management decisions and subsequently shorten the time from diagnosis to treatment.

High Tidal Volume, High Positive End Expiratory Pressure and Apneic Breath Hold Strategies (Lung Navigation Ventilation Protocol) With Cone Beam Computed Tomography Bronchoscopic Biopsy of Peripheral Lung Lesions: Results in 100 Patients

BACKGROUND

A dedicated anesthesia protocol for bronchoscopic lung biopsy-lung navigation ventilation protocol (LNVP)-specifically designed to mitigate atelectasis and reduce unnecessary respiratory motion, has been recently described. LNVP demonstrated significantly reduced dependent ground glass, sublobar/lobar atelectasis, and atelectasis obscuring target lesions compared with conventional ventilation.

METHODS

In this retrospective, single-center study, we examine the impact of LNVP on 100 consecutive patients during peripheral lung lesion biopsy. We report the incidence of atelectasis using cone beam computed tomography imaging, observed ventilatory findings, anesthesia medications, and outcomes, including diagnostic yield, radiation exposure, and complications.

RESULTS

Atelectasis was observed in a minority of subjects: ground glass opacity atelectasis was seen in 30 patients by reader 1 (28%) and in 18 patients by reader 2 (17%), with good agreement between readers (κ = 0.78). Sublobar/lobar atelectasis was observed in 23 patients by reader 1 and 26 patients by reader 2, also demonstrating good agreement (κ = 0.67). Atelectasis obscured target lesions in very few cases: 0 patients (0%, reader 1) and 3 patients (3%, reader 2). Diagnostic yield was 85.9% based on the AQuIRE definition. Pathology demonstrated 57 of 106 lesions (54%) were malignant, 34 lesions (32%) were benign, and 15 lesions (14%) were nondiagnostic.

CONCLUSION

Cone beam computed tomography images confirmed low rates of atelectasis, high tool-in-lesion confirmation rate, and high diagnostic yield. LNVP has a similar safety profile to conventional bronchoscopy. Most patients will require intravenous fluid and vasopressor support. Further study of LNVP and other ventilation protocols are necessary to understand the impact of ventilation protocols on bronchoscopic peripheral lung biopsy.

Virtual bronchoscopic navigation with intraoperative cone-beam CT for the diagnosis of peripheral pulmonary nodules

OBJECTIVE

Transbronchial biopsy is a safe manner with fewer complications than percutaneous transthoracic needle biopsy; however, the current diagnostic yield is still necessitating further improvement. We aimed to evaluate the diagnostic yield of using virtual bronchoscopic navigation (VBN) and cone-beam CT (CBCT) for transbronchial biopsy and to investigate the factors that affected the diagnostic sensitivity.

METHODS

We retrospectively investigated 255 patients who underwent VBN-CBCT-guided transbronchial biopsy at our two centers from May 2021 to April 2022. A total of 228 patients with final diagnoses were studied. Patient characteristics including lesion size, lesion location, presence of bronchus sign, lesion type and imaging tool used were collected and analyzed. Diagnostic yield was reported overall and in groups using different imaging tools.

RESULTS

The median size of lesion was 21 mm (range of 15.5-29 mm) with 46.1% less than 2 cm in diameter. Bronchus sign was present in 87.7% of the patients. The overall diagnostic yield was 82.1%, and sensitivity for malignancy was 66.3%. Patients with lesion > 2 cm or with bronchus sign were shown to have a significantly higher diagnostic yield. Four patients had bleeding and no pneumothorax occurred.

CONCLUSION

Guided bronchoscopy with VBN and CBCT was an effective diagnostic method and was associated with a high diagnostic yield in a safe manner. In addition, the multivariant analysis suggested that lesion size and presence of bronchus sign could be a predictive factor for successful bronchoscopic diagnosis.

New developments in the imaging of lung cancer

Radiological and nuclear medicine methods play a fundamental role in the diagnosis and staging of patients with lung cancer. Imaging is essential in the detection, characterisation, staging and follow-up of lung cancer. Due to the increasing evidence, low-dose chest computed tomography (CT) screening for the early detection of lung cancer is being introduced to the clinical routine in several countries. Radiomics and radiogenomics are emerging fields reliant on artificial intelligence to improve diagnosis and personalised risk stratification. Ultrasound- and CT-guided interventions are minimally invasive methods for the diagnosis and treatment of pulmonary malignancies. In this review, we put more emphasis on the new developments in the imaging of lung cancer.

Imaging modalities during navigational bronchoscopy

INTRODUCTION

Lung nodules are commonly encountered in clinical practice. Technological advances in navigational bronchoscopy and imaging modalities have led to paradigm shift from nodule screening or follow-up to early lung cancer detection. This is due to improved nodule localization and biopsy confirmation with combined modalities of navigational platforms and imaging tools. To conduct this article, relevant literature was reviewed via PubMed from January 2014 until January 2024.

AREAS COVERED

This article highlights the literature on different imaging modalities combined with commonly used navigational platforms for diagnosis of peripheral lung nodules. Current limitations and future perspectives of imaging modalities will be discussed.

EXPERT OPINION

The development of navigational platforms improved localization of targets. However, published diagnostic yield remains lower compared to percutaneous-guided biopsy. The discordance between the actual location of lung nodule during the procedure and preprocedural CT chest is the main factor impacting accurate biopsies. The utilization of advanced imaging tools with navigation-based bronchoscopy has been shown to assist with localizing targets in real-time and improving biopsy success. However, it is important for interventional bronchoscopists to understand the strengths and limitations of these advanced imaging technologies.

UBES: Unified scatter correction using ultrafast Boltzmann equation solver for conebeam CT

A semi-analytical solution to the unified Boltzmann equation is constructed to exactly describe the scatter distribution on a flat-panel detector for high-quality conebeam CT (CBCT) imaging. The solver consists of three parts, including the phase space distribution estimator, the effective source constructor and the detector signal extractor. Instead of the tedious Monte Carlo solution, the derived Boltzmann equation solver achieves ultrafast computational capability for scatter signal estimation by combining direct analytical derivation and time-efficient one-dimensional numerical integration over the trajectory along each momentum of the photon phase space distribution. The execution of scatter estimation using the proposed ultrafast Boltzmann equation solver (UBES) for a single projection is finalized in around 0.4 seconds. We compare the performance of the proposed method with the state-of-the-art schemes, including a time-expensive Monte Carlo (MC) method and a conventional kernel-based algorithm using the same dataset, which is acquired from the CBCT scans of a head phantom and an abdominal patient. The evaluation results demonstrate that the proposed UBES method achieves comparable correction accuracy compared with the MC method, while exhibits significant improvements in image quality over learning and kernel-based methods. With the advantages of MC equivalent quality and superfast computational efficiency, the UBES method has the potential to become a standard solution to scatter correction in high-quality CBCT reconstruction.

Chinese expert consensus on cone-beam CT-guided diagnosis, localization and treatment for pulmonary nodules

Cone-beam computed tomography (CBCT) system can provide real-time 3D images and fluoroscopy images of the region of interest during the operation. Some systems can even offer augmented fluoroscopy and puncture guidance. The use of CBCT for interventional pulmonary procedures has grown significantly in recent years, and numerous clinical studies have confirmed the technology's efficacy and safety in the diagnosis, localization, and treatment of pulmonary nodules. In order to optimize and standardize the technical specifications of CBCT and guide its application in clinical practice, the consensus statement has been organized and written in a collaborative effort by the Professional Committee on Interventional Pulmonology of China Association for Promotion of Health Science and Technology.

Using cryoprobes of different sizes combined with cone-beam computed tomography-derived augmented fluoroscopy and endobronchial ultrasound to diagnose peripheral pulmonary lesions: a propensity-matched study

BACKGROUND

Endobronchial ultrasound (EBUS) and cone-beam computed tomography-derived augmented fluoroscopy (CBCT-AF) are utilized for the diagnosis of peripheral pulmonary lesions (PPLs). Combining them with transbronchial cryobiopsy (TBC) can provide sufficient tissue for genetic analysis. However, cryoprobes of different sizes have varying degrees of flexibility, which can affect their ability to access the target bronchus and potentially impact the accuracy. The aim of this study was to compare the diagnostic efficacy of cryoprobes of varying sizes in CBCT-AF and EBUS for the diagnosis of PPLs.

METHODS

Patients who underwent endobronchial ultrasound-guided transbronchial biopsy (EBUS-TBB) and TBC combined with CBCT-AF for PPLs diagnosis between January 2021 and May 2022 were included. Propensity score matching and competing-risks regression were utilized for data analysis. Primary outcome was the diagnostic accuracy of TBC.

RESULTS

A total of 284 patients underwent TBC, with 172 using a 1.7-mm cryoprobe (1.7 group) and 112 using a 1.1-mm cryoprobe (1.1 group). Finally, we included 99 paired patients following propensity score matching. The diagnostic accuracy of TBC was higher in the 1.1 group (80.8% vs. 69.7%, P = 0.050), with a similar rate of complications. Subgroup analysis also revealed that the 1.1 group had better accuracy when PPLs were located in the upper lobe (85.2% vs. 66.1%, P = 0.020), when PPLs were smaller than 20 mm (78.8% vs. 48.8%, P = 0.008), and when intra-procedural CBCT was needed to be used (79.5% vs. 42.3%, P = 0.001). TBC obtained larger specimens than TBB in both groups. There is still a trend of larger sample size obtained in the 1.7 group, but there is no statistically different between our two study groups (40.8 mm2 vs. 22.0 mm2, P = 0.283).

CONCLUSIONS

The combination of TBC with CBCT-AF and EBUS is effective in diagnosing PPLs, and a thin cryoprobe is preferred when the PPLs located in difficult areas.

Severity of Atelectasis during Bronchoscopy: Descriptions of a New Grading System (AtelectasisSeverity Scoring System-"ASSESS") and At-Risk-Lung Zones

Atelectasis during bronchoscopy under general anesthesia is very common and can have a detrimental effect on navigational and diagnostic outcomes. While the intraprocedural incidence and anatomic location have been previously described, the severity of atelectasis has not. We reviewed chest CT images of patients who developed atelectasis in the VESPA trial (Ventilatory Strategy to Prevent Atelectasis). By drawing boundaries at the posterior chest wall (A), the anterior aspect of the vertebral body (C), and mid-way between these two lines (B), we delineated at-risk lung zones 1, 2, and 3 (from posterior to anterior). An Atelectasis Severity Score System ("ASSESS") was created, classifying atelectasis as "mild" (zone 1), "moderate" (zones 1-2), and "severe" (zones 1-2-3). A total of 43 patients who developed atelectasis were included in this study. A total of 32 patients were in the control arm, and 11 were in the VESPA arm; 20 patients (47%) had mild atelectasis, 20 (47%) had moderate atelectasis, and 3 (6%) had severe atelectasis. A higher BMI was associated with increased odds (1.5 per 1 unit change; 95% CI, 1.10-2.04) (p = 0.0098), and VESPA was associated with decreased odds (0.05; 95% CI, 0.01-0.47) (p = 0.0080) of developing moderate to severe atelectasis. ASSESS is a simple method used to categorize intra-bronchoscopy atelectasis, which allows for a qualitative description of this phenomenon to be developed. In the VESPA trial, a higher BMI was not only associated with increased incidence but also increased severity of atelectasis, while VESPA had the opposite effect. Preventive strategies should be strongly considered in patients with risk factors for atelectasis who have lesions located in zones 1 and 2, but not in zone 3.

Cone-Beam Computed Tomography-Guided Cryobiopsy Combined with Conventional Biopsy for Ground Glass Opacity-Predominant Pulmonary Nodules

INTRODUCTION

Cryobiopsy (CB) using a 1.1-mm cryoprobe under fluoroscopic guidance is feasible and safe for diagnosis of ground glass opacity (GGO) lesions. However, the efficacy of CB combined with cone-beam CT (CBCT) for GGO-predominant pulmonary nodules remains elusive.

METHODS

We retrospectively studied patients who underwent CB combined with conventional biopsy under CBCT guidance for GGO-predominant pulmonary nodules with a consolidation-to-tumour ratio <50.0%.

RESULTS

A total of 32 patients with GGO-predominant pulmonary nodules were enrolled: 17 pure GGOs and 15 mixed GGOs. The mean lesion diameter was 15.81 ± 5.52 mm and the overall diagnostic yield was 71.9%. Seven lesions were diagnosed by CB alone, which increased the diagnostic outcomes by 21.9%. Diagnostic yields for CB, forceps biopsy (FB), brushing, and guide sheath flushing were 65.6%, 46.9%, 15.6%, and 14.3%, respectively. Univariate analysis revealed that positive computed tomography (CT) bronchus sign (p = 0.035), positive CBCT sign (p < 0.01), and CB-first biopsy sequence (p = 0.036) were significant predictive factors for higher diagnostic yield. Specimens obtained by CB had larger mean sample size (p < 0.01), lower blood cell area (p < 0.01), and fewer crush artefacts (p < 0.01) than specimens from FB. No severe bleeding or other complications occurred.

CONCLUSION

CB using a 1.1-mm cryoprobe under CBCT guidance increased diagnostic yield for GGO-predominant pulmonary nodules based on conventional biopsy. Further, it provided larger and nearly intact samples compared with forceps.

[Advanced bronchoscopic techniques for the diagnosis of peripheral lung nodule]

The endoscopic diagnosis of peripheral lung nodules is a challenging aspect of oncological practice. More often than not inaccessible by traditional endoscopy, these nodules necessitate multiple imagery tests, as well as diagnostic surgery for benign lesions. Even though transthoracic ultrasonography has a high diagnostic yield, a sizeable complication rate renders it suboptimal. Over recent years, a number of safe and accurate navigational bronchoscopic procedures have been developed. In this first part, we provide an overview of the bronchoscopic techniques currently applied for the excision and diagnostic analysis of peripheral lung nodules; emphasis is laid on electromagnetic navigation bronchoscopy and the association of virtual bronchoscopy planner with radial endobronchial ultrasound. We conclude by considering recent innovations, notably robotic bronchoscopy.

Diagnostic Yield of Cone-beam-Derived Augmented Fluoroscopy and Ultrathin Bronchoscopy Versus Conventional Navigational Bronchoscopy Techniques

BACKGROUND

Pulmonary nodules suspicious for lung cancer are frequently diagnosed. Evaluating and optimizing the diagnostic yield of lung nodule biopsy is critical as innovation in bronchoscopy continues to progress.

METHODS

This is a retrospective cohort study. Consecutive patients undergoing guided bronchoscopy for suspicious pulmonary nodule(s) between February 2020 and July 2021 were included. The cone-beam computed tomography (CBCT)+ radial endobronchial ultrasound (r-EBUS) group had their procedure using CBCT-derived augmented fluoroscopy along with r-EBUS. The CBCT+ ultrathin bronchoscope (UTB)+r-EBUS group had the same procedure but with the use of an ultrathin bronchoscope. The r-EBUS group underwent r-EBUS guidance without CBCT or augmented fluoroscopy. We used multivariable logistic regression to compare diagnostic yield, adjusting for confounding variables.

RESULTS

A total of 116 patients were included. The median pulmonary lesion diameter was 19.5 mm (interquartile range, 15.0 to 27.5 mm), and 91 (78.4%) were in the peripheral half of the lung. Thirty patients (25.9%) underwent CBCT+UTB, 27 (23.3%) CBCT, and 59 (50.9%) r-EBUS alone with unadjusted diagnostic yields of 86.7%, 70.4%, and 42.4%, respectively ( P <0.001). The adjusted diagnostic yields were 85.0% (95% CI, 68.6% to 100%), 68.3% (95% CI, 50.1% to 86.6%), and 44.5% (95% CI, 31.0% to 58.0%), respectively. There was significantly more virtual navigational bronchoscopy use in the r-EBUS group (45.8%) compared with the CBCT+UTB (13.3%) and CBCT (18.5%) groups, respectively. CBCT procedures required dose area product radiation doses of 7602.5 µGym 2 .

CONCLUSION

Compared with the r-EBUS group, CBCT + UTB + r-EBUS was associated with higher navigational success, fewer nondiagnostic biopsy results, and a higher diagnostic yield. CBCT procedures are associated with a considerable radiation dose.

Radiation dose of cone beam CT combined with shape sensing robotic assisted bronchoscopy for the evaluation of pulmonary lesions: an observational single center study

Background

Shape sensing robotic-assisted bronchoscopy (ssRAB) combined with radial endobronchial ultrasound (r-EBUS) and cone beam computed tomography (CBCT) is a newer diagnostic modality for the evaluation of pulmonary lesions. There is limited data describing the radiation dose of CBCT combined with ssRAB. The purpose of this study was to describe the technical factors associated with the use of CBCT combined with ssRAB to biopsy pulmonary lesions.

Methods

We conducted a single center, prospective observational study of patients undergoing ssRAB combined with fixed CBCT for the pulmonary lesion biopsy. We report our patient demographics, and pulmonary lesion and procedure characteristics.

Results

A total of 241 ssRAB procedures were performed to biopsy 269 pulmonary lesions. The mean lesion size was measured in the following dimensions: anteroposterior (18.0±8.8 mm), transverse (17.2±10.5 mm), and craniocaudal (17.7±10.2 mm). A mean of 1.5±0.7 (median: 1, range: 1-4) CBCT spins were performed. The mean total fluoroscopy time (FT) was 5.6±2.9 minutes. The mean radiation dose of cumulative air kerma (CAK) was 63.5±46.7 mGy and the mean cumulative dose area product (DAP) was 22.6±16.0 Gy·cm2. Diagnostic yield calculated based on results at index bronchoscopy was 85.9%. There was a low rate of complications with 8 pneumothoraces (3.3%), 5 (2.1%) of which required chest tube placement.

Conclusions

We describe the use of ssRAB combined with CBCT to biopsy pulmonary lesions as a safe diagnostic modality with relatively low radiation dose that is potentially comparable to other image guided sampling modalities. Bronchoscopists should be cognizant of the radiation use during the procedure for both patient and staff safety.

Robotic bronchoscopy in diagnosing lung cancer-the evidence, tips and tricks: a clinical practice review

The development of robotic-assisted bronchoscopy has empowered bronchoscopists to access the periphery of the lung with more confidence and promising accuracy. This is due in large to the superior maneuverability, further reach, and stability of these technologies. Despite the advantages of robotic bronchoscopy, there are some drawbacks to using these technologies, such as the loss of tactile feedback, the need to overcome computed tomography (CT)-to-body divergence, and the potential for overreliance on the navigation software. There are currently two robotic bronchoscopy platforms on the US market, the MonarchTM Platform by Auris Health© (Redwood City, CA, USA) and the IonTM endoluminal robotic bronchoscopy platform by Intuitive Surgical© (Sunnyvale, CA, USA). In this clinical practice review, we highlight the evidence and strategies for successful clinical use of both robotic bronchoscopy platforms for pulmonary lesion sampling. Specifically, we will review pre-procedural considerations, such as procedural mapping, room set-up and anesthesia considerations. We will also review the technical aspects of using the robotic bronchoscopy platforms, such as how to compensate for the loss of tactile feedback, optimize visualization, use of ancillary technology to accommodate for CT-to-body divergence, employ best practices for sampling techniques, and utilize information from rapid on-site evaluation (ROSE) to aid in improving diagnostic yield.

Cone-beam CT in lung biopsy: a clinical practice review on lessons learned and future perspectives

Pulmonary nodules with intermediate to high risk of malignancy should preferably be diagnosed with image guide minimally invasive diagnostics before treatment. Several technological innovations have been developed to endobronchially navigate to these lesions and obtain tissue for diagnosis. This review addresses these technological advancements in navigation bronchoscopy in three basic steps: navigation, position confirmation and acquisition, with a specific focus on cone-beam computed tomography (CBCT). For navigation purposes ultrathin bronchoscopy combined with virtual bronchoscopy navigation, electromagnetic navigation and robotic assisted bronchoscopy all achieve good results as a navigation guidance tool, but cannot confirm location or guide biopsy positioning. Diagnostic yield has seen improvement by combining these techniques with a secondary imaging tool like radial endobronchial ultrasound (rEBUS) and fluoroscopy. For confirmation of lesion access, rEBUS provides local detailed ultrasound-imaging and can be used to confirm lesion access in combination with fluoroscopy, measure nodule-contact area length and determine catheter position for sampling. CBCT is the only technology that can provide precise 3D positioning confirmation. When focusing on tissue acquisition, there is often more than 10% difference between reaching the target and getting a diagnosis. This discrepancy is multifactorial and caused by breathing movements, small samples sizes, instrument tip displacements by tool rigidity and tumour inhomogeneity. Yield can be improved by targeting fluorodeoxyglucose (FDG)-avid regions, immediate feedback of rapid onsite evaluation, choosing sampling tools with different passive stiffnesses, by increasing the number biopsies taken and (future) catheter modifications like (robotic assisted-) active steering. CBCT with augmented fluoroscopy (CBCT-AF) based navigation bronchoscopy combines navigation guidance with 3D-image confirmation of instrument-in-lesion positioning in one device. CBCT-AF allows for overlaying the lesion and navigation pathway and the possibility to outline trans-parenchymal pathways. It can help guide and verify sampling in 3D in near real-time. Disadvantages are the learning curve, the inherent use of radiation and limited availability/access to hybrid theatres. A mobile C-arm can provide 3D imaging, but lower image quality due to lower power and lower contrast-to-noise ratio is a limiting factor. In conclusion, a multi-modality approach in experienced hands seems the best option for achieving a diagnostic accuracy >85%. Either adequate case selection or detailed 3D imaging are essential to obtain high accuracy. For current and future transbronchial treatments, high-resolution (CBCT) 3D-imaging is essential.

Digital Tomosynthesis: Review of Current Literature and Its Impact on Diagnostic Bronchoscopy

Bronchoscopy has garnered increased popularity in the biopsy of peripheral lung lesions. The development of navigational guided bronchoscopy systems along with radial endobronchial ultrasound (REBUS) allows clinicians to access and sample peripheral lesions. The development of robotic bronchoscopy improved localization of targets and diagnostic accuracy. Despite such technological advancements, published diagnostic yield remains lower compared to computer tomography (CT)-guided biopsy. The discordance between the real-time location of peripheral lesions and anticipated location from preplanned navigation software is often cited as the main variable impacting accurate biopsies. The utilization of cone beam CT (CBCT) with navigation-based bronchoscopy has been shown to assist with localizing targets in real-time and improving biopsy success. The resources, costs, and radiation associated with CBCT remains a hindrance in its wider adoption. Recently, digital tomosynthesis (DT) platforms have been developed as an alternative for real-time imaging guidance in peripheral lung lesions. In North America, there are several commercial platforms with distinct features and adaptation of DT. Early studies show the potential improvement in peripheral lesion sampling with DT. Despite the results of early observational studies, the true impact of DT-based imaging devices for peripheral lesion sampling cannot be determined without further prospective randomized trials and meta-analyses.

Possible Use of Linear Echobronchoscope for Diagnosis of Peripheral Pulmonary Nodules

Echobronchoscope-guided transbronchial needle aspiration (EBUS-TBNA) is mainly used as the transbronchial approach to hilar/mediastinal lymph nodes or lesions, for diagnostic or staging purposes. Moreover, the role of linear EBUS-TBNA as a diagnostic tool for central intrapulmonary lesions adjacent to the trachea or the major bronchi is also well established. However, since the tip of the ultrasound probe at the distal end of the echobronchoscope is very thin, it can be wedged through smaller peripheral bronchi, reaching the distal parenchyma and allowing for peripheral pulmonary lesion sampling. The main aim of this retrospective study was to evaluate the diagnostic yield and the safety of EBUS-TBNA in the diagnosis of pulmonary peripheral nodules. The database of the Interventional Pulmonology Unit of Azienda Ospedaliero-Universitaria delle Marche (Ancona, Italy) was evaluated to identify peripheral pulmonary nodules approached by EBUS-TBNA. Thirty patients with a single peripheral pulmonary nodule located peripherally to the subsegmental bronchi of the lower lobes and adjacent to a small bronchus greater than 3 mm in diameter were included in this study. The nodule was visible using endoscopic ultrasound in 28 patients and the diagnosis was obtained via EBUS-TBNA in 26 cases (12 adenocarcinoma, 5 typical carcinoid tumors, 4 hamartoma and 5 metastatic lesions). The diagnostic yield was 86.6% for all 30 patients and 92.8% if only the 28 patients in which the lesion was visualized via echobronchoscopy were considered. No relevant adverse events were observed. We conclude that EBUS-TBNA may be an effective and safe option to sample pulmonary peripheral nodules in selected patients with lower lobe peripheral pulmonary lesions adjacent to small bronchi greater than 3 mm in diameter and reachable with the EBUS-TBNA probe.

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.

Advanced Imaging for Robotic Bronchoscopy: A Review

Recent advances in navigational platforms have led bronchoscopists to make major strides in diagnostic interventions for pulmonary parenchymal lesions. Over the last decade, multiple platforms including electromagnetic navigation and robotic bronchoscopy have allowed bronchoscopists to safely navigate farther into the lung parenchyma with increased stability and accuracy. Limitations persist, even with these newer technologies, in achieving a similar or higher diagnostic yield when compared to the transthoracic computed tomography (CT) guided needle approach. One of the major limitations to this effect is due to CT-to-body divergence. Real-time feedback that better defines the tool-lesion relationship is vital and can be obtained with additional imaging using radial endobronchial ultrasound, C-arm based tomosynthesis, cone-beam CT (fixed or mobile), and O-arm CT. Herein, we describe the role of this adjunct imaging with robotic bronchoscopy for diagnostic purposes, describe potential strategies to counteract the CT-to-body divergence phenomenon, and address the potential role of advanced imaging for lung tumor ablation.

Cone-beam computed tomography-guided endobronchial ultrasound using an ultrathin bronchoscope for diagnosis of peripheral pulmonary lesions: a prospective pilot study

Background

Multimodal transbronchial biopsy (TBB) may have improved diagnostic yield for peripheral pulmonary lesions suspected as lung cancer. Radial endobronchial ultrasound (R-EBUS) provides real-time imaging and confirmation of the location of the lesions. Cone-beam computed tomography (CBCT) can confirm that the forceps tip has reached the lesion before biopsy.

Methods

Patients with peripheral pulmonary lesions and a positive computed tomography (CT) bronchus sign (based on slice thickness of 1 mm) were prospectively enrolled. An ultrathin bronchoscope (UTB) and R-EBUS probe were advanced to the target bronchus. Thereafter, forceps were advanced, and CBCT was performed. R-EBUS was performed for re-navigation, if possible. The obtained EBUS and CBCT images were classified into "within" (type 1), "adjacent to" (type 2), or "far from" (type 3), based on the probe or forceps tip.

Results

For 20 lesions, the diagnostic yield was 85%. The primary EBUS images were of types 1, 2, and 3 in 12, 6, and 2 cases, respectively. The primary CBCT images were of types 1, 2, and 3 in 12, 6, and 2 cases, respectively. Primary EBUS and CBCT image types were equivalent in 14 cases. Of the 12 cases with type 1 primary EBUS image, 9 cases had a type 1 primary CBCT image, while 3 cases exhibited positional misalignment of the forceps tip. Re-navigation was required in 8 cases with types 2 and 3 primary CBCT images.

Conclusions

CBCT-guided TBB using an UTB and EBUS may enable real-time positioning guidance and better re-navigation in the diagnosis of peripheral pulmonary lesions.

Mobile Cone-Beam CT-Assisted Bronchoscopy for Peripheral Lung Lesions

Peripheral bronchoscopy with the use of thin/ultrathin bronchoscopes and radial-probe endobronchial ultrasound (RP-EBUS) has been associated with a fair diagnostic yield. Mobile cone-beam CT (m-CBCT) could potentially improve the performance of these readily available technologies. We retrospectively reviewed the records of patients undergoing bronchoscopy for peripheral lung lesions with thin/ultrathin scope, RP-EBUS, and m-CBCT guidance. We studied the performance (diagnostic yield and sensitivity for malignancy) and safety (complications, radiation exposure) of this combined approach. A total of 51 patients were studied. The mean target size was 2.6 cm (SD, 1.3 cm) and the mean distance to the pleura was 1.5 cm (SD, 1.4 cm). The diagnostic yield was 78.4% (95 CI, 67.1-89.7%), and the sensitivity for malignancy was 77.4% (95 CI, 62.7-92.1%). The only complication was one pneumothorax. The median fluoroscopy time was 11.2 min (range, 2.9-42.1) and the median number of CT spins was 1 (range, 1-5). The mean Dose Area Product from the total exposure was 41.92 Gy·cm² (SD, 11.35 Gy·cm²). Mobile CBCT guidance may increase the performance of thin/ultrathin bronchoscopy for peripheral lung lesions in a safe manner. Further prospective studies are needed to corroborate these findings.

Endoscopic Technologies for Peripheral Pulmonary Lesions: From Diagnosis to Therapy

Peripheral pulmonary lesions (PPLs) are frequent incidental findings in subjects when performing chest radiographs or chest computed tomography (CT) scans. When a PPL is identified, it is necessary to proceed with a risk stratification based on the patient profile and the characteristics found on chest CT. In order to proceed with a diagnostic procedure, the first-line examination is often a bronchoscopy with tissue sampling. Many guidance technologies have recently been developed to facilitate PPLs sampling. Through bronchoscopy, it is currently possible to ascertain the PPL's benign or malignant nature, delaying the therapy's second phase with radical, supportive, or palliative intent. In this review, we describe all the new tools available: from the innovation of bronchoscopic instrumentation (e.g., ultrathin bronchoscopy and robotic bronchoscopy) to the advances in navigation technology (e.g., radial-probe endobronchial ultrasound, virtual navigation, electromagnetic navigation, shape-sensing navigation, cone-beam computed tomography). In addition, we summarize all the PPLs ablation techniques currently under experimentation. Interventional pulmonology may be a discipline aiming at adopting increasingly innovative and disruptive technologies.

Enhancing Nodule Biopsy Through Technology Integration

Technology in navigating to peripheral pulmonary nodules has improved in recent years. The recent integration of a robotic platform using shape-sensing technology and mobile cone-beam computed tomography imaging technology has enhanced confidence in sampling lesions with intraprocedural imaging by complimenting the pre-planned navigation to peripheral pulmonary nodules. We present 2 cases using the software integration that improved the robotic catheter positioning to allow for diagnostic specimens to be obtained in the initial biopsies.

Ventilatory Strategy to Prevent Atelectasis During Bronchoscopy Under General Anesthesia: A Multicenter Randomized Controlled Trial (Ventilatory Strategy to Prevent Atelectasis -VESPA- Trial)

BACKGROUND

Atelectasis negatively influences peripheral bronchoscopy, increasing CT scan-body divergence, obscuring targets, and creating false-positive radial-probe endobronchial ultrasound (RP-EBUS) images.

RESEARCH QUESTION

Can a ventilatory strategy reduce the incidence of atelectasis during bronchoscopy under general anesthesia?

STUDY DESIGN AND METHODS

Randomized controlled study (1:1) in which patients undergoing bronchoscopy were randomized to receive standard ventilation (laryngeal mask airway, 100% Fio2, zero positive end-expiratory pressure [PEEP]) vs a ventilatory strategy to prevent atelectasis (VESPA) with endotracheal intubation followed by a recruitment maneuver, Fio2 titration (< 100%), and PEEP of 8 to 10 cm H2O. All patients underwent chest CT imaging and a survey for atelectasis with RP-EBUS bilaterally on bronchial segments 6, 9, and 10 after artificial airway insertion (time 1) and 20 to 30 min later (time 2). Chest CT scans were reviewed by a blinded chest radiologist. RP-EBUS images were assessed by three independent, blinded readers. The primary end point was the proportion of patients with any atelectasis (either unilateral or bilateral) at time 2 according to chest CT scan findings.

RESULTS

Seventy-six patients were analyzed, 38 in each group. The proportion of patients with any atelectasis according to chest CT scan at time 2 was 84.2% (95% CI, 72.6%-95.8%) in the control group and 28.9% (95% CI, 15.4%-45.9%) in the VESPA group (P < .0001). The proportion of patients with bilateral atelectasis at time 2 was 71.1% (95% CI, 56.6%-85.5%) in the control group and 7.9% (95% CI, 1.7%-21.4%) in the VESPA group (P < .0001). At time 2, 3.84 ± 1.67 (mean ± SD) bronchial segments in the control group vs 1.21 ± 1.63 in the VESPA group were deemed atelectatic (P < .0001). No differences were found in the rate of complications.

INTERPRETATION

VESPA significantly reduced the incidence of atelectasis, was well tolerated, and showed a sustained effect over time despite bronchoscopic nodal staging maneuvers. VESPA should be considered for bronchoscopy when atelectasis is to be avoided.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT04311723; URL: www.

CLINICALTRIALS

gov.

Diagnosis of Organizing Pneumonia with an Ultrathin Bronchoscope and Cone-Beam CT: A Case Report

Organizing pneumonia (OP) is a pulmonary disease histopathologically characterized by plugs of loose connective tissue in distal airways. The clinical and radiological presentations are not specific and they usually require a biopsy confirmation. This paper presents the case of a patient with a pulmonary opacity sampled with a combined technique of ultrathin bronchoscopy and cone-beam CT. A 64-year-old female, a former smoker, was admitted to the hospital of Reggio Emilia (Italy) for exertional dyspnea and a dry cough without a fever. The history of the patient included primary Sjögren Syndrome interstitial lung disease (pSS-ILD) characterized by a non-specific interstitial pneumonia (NSIP) radiological pattern; this condition was successfully treated up to 18 months before the new admission. The CT scan showed the appearance of a right lower lobe pulmonary opacity of an uncertain origin that required a histological exam for the diagnosis. The lung lesion was difficult to reach with traditional bronchoscopy and a percutaneous approach was excluded. Thus, cone-beam CT, augmented fluoroscopy and ultrathin bronchoscopy were chosen to collect a tissue sample. The histopathological exam was suggestive of OP, a condition occurring in 4-11% of primary Sjögren Syndrome cases. This case showed that, in the correct clinical and radiological context, even biopsies taken with small forceps can lead to a diagnosis of OP. Moreover, it underlined that the combination of multiple advanced technologies in the same procedure can help to reach difficult target lesions, providing proper samples for a histological diagnosis.

Advancements in navigational bronchoscopy for peripheral pulmonary lesions: A review with special focus on virtual bronchoscopic navigation

Lung cancer is often diagnosed at an advanced stage and is associated with significant morbidity and mortality. Low-dose computed tomography for lung cancer screening has increased the incidence of peripheral pulmonary lesions. Surveillance and early detection of these lesions at risk of developing cancer are critical for improving patient survival. Because these lesions are usually distal to the lobar and segmental bronchi, they are not directly visible with standard flexible bronchoscopes resulting in low diagnostic yield for small lesions <2 cm. The past 30 years have seen several paradigm shifts in diagnostic bronchoscopy. Recent technological advances in navigation bronchoscopy combined with other modalities have enabled sampling lesions beyond central airways. However, smaller peripheral lesions remain challenging for bronchoscopic biopsy. This review provides an overview of recent advances in interventional bronchoscopy in the screening, diagnosis, and treatment of peripheral pulmonary lesions, with a particular focus on virtual bronchoscopic navigation.

Cone beam CT-guided navigation bronchoscopy: a cost-effective alternative to CT-guided transthoracic biopsy for diagnosis of peripheral pulmonary nodules

Objectives

To determine if cone beam CT-guided navigation bronchoscopy (CBCT-NB) is a cost-effective diagnostic procedure in patients with a pulmonary nodule (PN) with an intermediate risk for lung cancer.

Materials and methods

Two decision analytical models were developed to compare the long-term costs, survival and quality of life. In the first model, CBCT-NB was compared with CT-guided transthoracic needle biopsy (TTNB) in TTNB eligible patients. In the second model, CBCT-NB was compared with direct treatment (without pathology proven lung cancer) in patients for whom TTNB is not suitable. Input data were gathered in-house, from literature and expert opinion. Effects were expressed in quality-adjusted life years (QALYs). Sensitivity analyses were used to assess uncertainty.

Results

CBCT-NB can be cost-effective in TTNB eligible patients with an incremental cost-effectiveness ratio of €18 416 in an expert setting. The probabilistic sensitivity analysis showed that in 69% and 90% of iterations CBCT-NB remained cost-effective assuming a willingness to pay (WTP) of €20 000 and €80 000 per QALY. CBCT-NB dominated in the treatment strategy in which TTNB is not suitable. The probabilistic sensitivity analysis showed that in 95% of iterations CBCT-NB remained the dominant strategy, and CBCT-NB remained cost-effective in 100% of iterations assuming a WTP limit of €20 000. In the comparison between CBCT NB and TTNB, the deterministic sensitivity analysis showed that the diagnostic properties and costs of both procedures have a large impact on the outcome.

Conclusions

CBCT-NB seems a cost-effective procedure when compared with TTNB and when compared with a direct treatment strategy in patients with an intermediate risk PN.

Efficacy and Safety of Cone-Beam CT Augmented Electromagnetic Navigation Guided Bronchoscopic Biopsies of Indeterminate Pulmonary Nodules

Bronchoscopic biopsy results for indeterminate pulmonary nodules remain suboptimal. Electromagnetic navigation bronchoscopy (ENB) coupled with cone beam computed tomography (CBCT) for confirmation has the potential to improve diagnostic yield. We present our experience using this multimodal approach to biopsy 17 indeterminate nodules in 14 consecutive patients from April to August 2021. Demographic information, nodule characteristics, and biopsy results were recorded. Procedures were performed in a hybrid operating room equipped with a Siemens Artis Q bi-plane CBCT (Siemens, Munich, Germany). After ENB using the superDimension version 7.1 (Medtronic, Plymouth, MN, USA) to target the lesion, radial endobronchial ultrasound was used as secondary confirmation. Next, transbronchial needle aspiration was performed prior to CBCT to evaluate placement of the biopsy tool in the lesion. The average nodule size was 21.7+/−15 mm with 59% (10/17) < 2 cm in all dimensions and 35% (6/17) showing a radiographic bronchus sign. The diagnostic yield of CBCT-guided ENB was 76% (13/17). No immediate periprocedural or postprocedural complications were identified. Our experience with CBCT-guided ENB further supports the comparable efficacy and safety of this procedure compared to other mature biopsy modalities. Studies designed to optimize the lung nodule biopsy process and to determine the contributions from different procedural aspects are warranted.

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.