Ultrathin Bronchoscopy with Multimodal Devices for Peripheral Pulmonary Lesions. A Randomized Trial

Pulmonary endoscopy - central to an interventional pulmonology program

INTRODUCTION

Pulmonary endoscopy occupies a central role in Interventional Pulmonology and is frequently the mainstay of diagnosis of respiratory disease, in particular lung malignancy. Older techniques such as rigid bronchoscopy maintain an important role in central airway obstruction. Renewed interest in the peripheral pulmonary nodule is driving major advances in technologies to increase the diagnostic accuracy and advance new potential endoscopic therapeutic options.

AREAS COVERED

This paper describes the role of pulmonary endoscopy, in particular ultrasound in the diagnosis and staging of lung malignancy. We will explore the recent expansion of ultrasound to include endoscopic ultrasound - bronchoscopy (EUS-B) and combined ultrasound (CUS) techniques. We will discuss in detail the advances in the workup of the peripheral pulmonary nodule.We performed a non-systematic, narrative review of the literature to summarize the evidence regarding the indications, diagnostic yield, and safety of current bronchoscopic sampling techniques.

EXPERT OPINION

EBUS/EUS-B has revolutionized the diagnosis and staging of thoracic malignancy resulting in more accurate assessment of the mediastinum compared to mediastinoscopy alone, thus reducing the rate of futile thoracotomies. Although major advances in the assessment of the peripheral pulmonary nodule have been made, the role of endoscopy in this area requires further clarification and investigation.

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.

Bronchial branch tracing navigation in ultrathin bronchoscopy-guided radial endobronchial ultrasound for peripheral pulmonary nodule

BACKGROUND

Most malignant peripheral pulmonary lesions (PPLs) are situated in the peripheral region of the lung. Although the ultrathin bronchoscope (UTB) can access these areas, a robust navigation system is essential for precise localisation of these small peripheral PPLs. Since many UTB procedures rely on automated virtual bronchoscopic navigation (VBN), this study aims to determine the accuracy and diagnostic yield of the manual bronchial branch tracing (BBT) navigation in UTB-guided radial endobronchial ultrasound (rEBUS) procedures.

METHODS

Single-centre retrospective study of UTB-rEBUS patients with PPLs smaller than 3 cm over a two year period.

RESULTS

Our cohort consisted of 47 patients with a mean age of 61.6 (SD 9.53) years and a mean target size of 1.91 (SD 0.53) cm. Among these lesions, 46.8% were located in the 6th airway generation, and 78.7% exhibited a direct bronchus sign. Navigation success using BBT was 91.5% based on positive rEBUS identification. The index diagnostic yield was 82.9%, increasing to 91.5% at 12 months of follow-up. Malignant lesions accounted for 65.1% of cases, while 34.9% were non-malignant. The presence of a direct bronchus sign was the sole factor associated with higher navigation success and diagnostic yield. Cryobiopsy outperformed forceps biopsy in non-concentric rEBUS lesions (90.9% vs. 50.0%, p < 0.05), but not in concentric orientated lesions. One pneumothorax occurred in our cohort.

CONCLUSIONS

BBT as an exclusive navigation method for small PPLs in UTB-rEBUS procedures has proved to be safe and feasible. Combination of UTB with cryobiopsy remains efficient for eccentric and adjacently oriented rEBUS lesions.

Clinical utility of rapid on-site evaluation of brush cytology during bronchoscopy using endobronchial ultrasound with a guide sheath

Previous studies have shown that rapid on-site evaluation (ROSE) improves the diagnostic yield of bronchoscopy using endobronchial ultrasound with a guide sheath (EBUS-GS) for peripheral pulmonary lesions (PPL). While ROSE of imprint cytology from forceps biopsy has been widely discussed, there are few reports on ROSE of brush cytology. This study investigated the utility of ROSE of brush cytology during bronchoscopy. We retrospectively analyzed data from 214 patients who underwent bronchoscopy with EBUS-GS for PPL. The patients in the ROSE group had significantly higher diagnostic sensitivity through the entire bronchoscopy process than in the non-ROSE group (96.8% vs. 83.3%, P = 0.002). The use of ROSE significantly increased the sensitivity of brush cytology with Papanicolaou staining (92.9% vs. 75.0%, P < 0.001). When ROSE was sequentially repeated on brushing specimens, initially negative ROSE results converted to positive in 79.5% of cases, and the proportion of specimens with high tumor cell counts increased from 42.1 to 69.0%. This study concludes that ROSE of brush cytology improves the diagnostic accuracy of bronchoscopy and enhances specimen quality through repeated brushing.

Value of ultrathin bronchoscope in improving the endobronchial ultrasound localization rate and diagnosing peripheral pulmonary nodules by cryobiopsy

BACKGROUND

A 3.0-mm ultrathin bronchoscope (UTB) with a 1.7-mm working channel provides better accessibility to peripheral bronchi. A 4.0-mm thin bronchoscope with a larger 2.0-mm working channel facilitates the use of a guide sheath (GS), ensuring repeated sampling from the same location. The 1.1-mm ultrathin cryoprobe has a smaller diameter, overcoming the limitation of the size of biopsy instruments used with UTB. In this study, we compared the endobronchial ultrasound localization rate and diagnostic yield of peripheral lung lesions by cryobiopsy using UTB and thin bronchoscopy combined with GS.

METHODS

We retrospectively evaluated 133 patients with peripheral pulmonary lesions with a diameter less than 30 mm who underwent bronchoscopy with either thin bronchoscope or UTB from May 2019 to May 2023. A 3.0-mm UTB combined with rEBUS was used in the UTB group, whereas a 4.0-mm thin bronchoscope combined with rEBUS and GS was used for the thin bronchoscope group. A 1.1-mm ultrathin cryoprobe was used for cryobiopsy in the two groups.

RESULTS

Among the 133 patients, peripheral pulmonary nodules in 85 subjects were visualized using r-EBUS. The ultrasound localization rate was significantly higher in the UTB group than in the thin bronchoscope group (96.0% vs. 44.6%, respectively; P < 0.001). The diagnostic yield of cryobiopsy specimens from the UTB group was significantly higher compared to the thin bronchoscope group (54.0% vs. 30.1%, respectively; p = 0.006). Univariate analysis demonstrated that the cryobiopsy diagnostic yields of the UTB group were significantly higher for lesions ≤ 20 mm, benign lesions, upper lobe lesions, lesions located lateral one-third from the hilum, and lesions without bronchus sign.

CONCLUSIONS

Ultrathin bronchoscopy combined with cryobiopsy has a superior ultrasound localization rate and diagnostic yield compared to a combination of cryobiopsy and thin bronchoscopy.

Evaluation of radiofrequency identification tag accuracy using bronchoscopy with fluoroscopy and virtual navigation guidance before segmentectomy

BACKGROUND

The use of sublobar resection has increased with advances in imaging technologies. However, it is difficult for thoracic surgeons to identify small lung tumours intraoperatively. Radiofrequency identification (RFID) lung-marking systems are useful for overcoming this difficulty; however, accurate placement is essential for maximum effectiveness.

METHODS

We retrospectively reviewed patients who underwent RFID tag placement via fluoroscopic bronchoscopy under virtual bronchoscopic navigation (VBN) guidance before our institution's sublobar resection of lung lesions. Thirty-one patients with 31 lung lesions underwent RFID lung-marking with fluoroscopic bronchoscopy under VBN guidance.

RESULTS

Of the 31 procedures, 26 tags were placed within 10 mm of the target site, 2 were placed more than 10 mm away from the target site, and 3 were placed in a different area from the target bronchus. No clinical complications were associated with RFID tag placement, such as pneumothorax or bleeding. The contribution of the RFID lung-marking system to surgery was high, particularly when the RFID tag was placed at the target site and tumour was located in the intermediate hilar zone.

CONCLUSIONS

An RFID tag can be placed near the target site using fluoroscopic bronchoscopy in combination with VBN guidance. RFID tag placement under fluoroscopic bronchoscopy with VBN guidance is useful for certain segmentectomies.

A pilot study of optical coherence tomography-guided transbronchial biopsy in peripheral pulmonary lesions

BACKGROUND

The diagnosis of peripheral pulmonary lesions (PPLs) remains challenging. Despite advancements in guided transbronchial biopsy (TBB) techniques, diagnostic yields haven't reached ideal levels. Optical coherence tomography (OCT) has been developed for application in pulmonary diseases, yet no data existed evaluating effectiveness in diagnosing PPLs.

RESEARCH DESIGN AND METHODS

This study included patients who underwent OCT and radial endobronchial ultrasound (R-EBUS)-guided TBB. OCT and R-EBUS imaging features were analyzed to differentiate between benign and malignant PPLs and subtypes of lung cancer.

RESULTS

A total of 89 patients were included in this study. The diagnostic yield of OCT-guided TBB stood at 56.18%, R-EBUS-guided TBB was 83.15% (P<0.01). The accuracy of OCT to judge the nature of lesions was 92.59%, while R-EBUS was 77.92%. The accuracy of OCT in predicting squamous carcinoma (SCC) and adenocarcinoma were both 91.30%.

CONCLUSIONS

Although the diagnostic yield of OCT-guided TBB fell short of that achieved by R-EBUS, OCT possessed the capability to judge the nature of lesions and guide the pathological classification of malignant lesions. Further extensive prospective studies are necessary to thoroughly assess the characteristics of this procedure.

CLINICAL TRIAL REGISTRATION

https://register.clinicaltrials.gov/ identifier is NCT06419114.

Comparison of cryobiopsy and forceps biopsy for the diagnosis of mediastinal lesions: A randomised clinical trial

INTRODUCTION

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is the standard approach for lung cancer staging. However, its diagnostic utility for other mediastinal diseases might be hampered by the limited tissue retrieved. Recent evidence suggests the novel sampling strategies of forceps biopsy and cryobiopsy as auxiliary techniques to EBUS-TBNA, considering their capacity for larger diagnostic samples.

METHODS

This study determined the added value of forceps biopsy and cryobiopsy for the diagnosis of mediastinal diseases. Consecutive patients with mediastinal lesions of 1 cm or more in the short axis were enrolled. Following completion of needle aspiration, three forceps biopsies and one cryobiopsy were performed in a randomised pattern. Primary endpoints included diagnostic yield defined as the percentage of patients for whom mediastinal biopsy led to a definite diagnosis, and procedure-related complications.

RESULTS

In total, 155 patients were recruited and randomly assigned. Supplementing EBUS-TBNA with either forceps biopsy or cryobiopsy increased diagnostic yield, with no significant difference between EBUS-TBNA plus forceps biopsy and EBUS-TBNA plus cryobiopsy (85.7 % versus 91.6 %, P = 0.106). Yet, samples obtained by additional cryobiopsies were more qualified for lung cancer molecular testing than those from forceps biopsies (100.0 % versus 89.5 %, P = 0.036). When compared directly, the overall diagnostic yield of cryobiopsy was superior to forceps biopsy (85.7 % versus 70.8 %, P = 0.001). Cryobiopsies produced greater samples in shorter procedural time than forceps biopsies. Two (1.3 %) cases of postprocedural pneumothorax were detected.

CONCLUSIONS

Transbronchial mediastinal cryobiopsy might be a promising complementary tool to supplement traditional needle biopsy for increased diagnostic yield and tissue harvesting.

TRIAL REGISTRATION

ChiCTR2000030373.

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.

Improving Cancer Probability Estimation in Nondiagnostic Bronchoscopies: A Meta-analysis

BACKGROUND

In patients with peripheral pulmonary lesions (PPLs), nondiagnostic bronchoscopy results are not uncommon. The conventional approach to estimate the probability of cancer (pCA) after bronchoscopy relies on dichotomous test assumptions, using prevalence, sensitivity, and specificity to determine negative predictive value. However, bronchoscopy is a multidisease test, raising concerns about the accuracy of dichotomous methods.

RESEARCH QUESTION

By how much does calculating pCA using a dichotomous approach (pCAdichotomous) underestimate the true pCA when applied to multidisease tests like bronchoscopy for the diagnosis of PPL?

METHODS

In this meta-analysis of cohort studies involving radial endobronchial ultrasound for PPL, Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed, constructing 2 × 2 contingency tables for calculating pCAdichotomous. For the multidisease test approach, 3 × 3 contingency tables for calculating probability of malignancy for a test that can have different categories of results and can diagnose multiple diseases (pCAmultidisease) using the likelihood ratio (LR) method for nondiagnostic results (LR(T0)) was used. Observed malignancy rates in patients with nondiagnostic results were compared with pCAdichotomous and pCAmultidisease.

RESULTS

In 46 studies (7,506 patients), malignancy was the underlying diagnosis in 76% of cases, another specific disease in 13% of cases, and nonspecific fibrosis or scar in 10% of cases. The percentage of patients with nondiagnostic results who had malignancy matched pCAmultidisease across all studies. In contrast, pCAdichotomous consistently underestimated cancer risk (median difference, 0.12; interquartile range, 0.06-0.23), particularly in studies with a higher prevalence of nonmalignant disease. The pooled LR(T0) was 0.46 (95% CI, 0.40-0.52; I2 = 76%; P < .001) and correlated with the prevalence of nonmalignant diseases (P = .001).

INTERPRETATION

Conventional dichotomous methods for estimating pCA after nondiagnostic bronchoscopies underestimate the likelihood of malignancy. Physicians should opt for the multidisease test approach when interpreting bronchoscopy results.

Novel diagnostic processes and challenges in bronchoscopy

Diagnostic bronchoscopy is a minimally invasive procedure that plays a crucial role in the diagnosis and management of various respiratory conditions. This paper explores the advancements in technology that have revolutionized the field and focuses on the new diagnostic procedures in bronchoscopy that have emerged in recent years. These innovative techniques have expanded the diagnostic capabilities of bronchoscopy, allowing for more accurate and comprehensive evaluation of respiratory conditions. This paper will also discuss the challenges in the diagnostic process with bronchoscope.

Development of the Korean Association for Lung Cancer Clinical Practice Guidelines: Recommendations on Radial Probe Endobronchial Ultrasound for Diagnosing Lung Cancer - An Updated Meta-Analysis

PURPOSE

Radial probe endobronchial ultrasound (RP-EBUS) accurately locates peripheral lung lesions (PLLs) during transbronchial biopsy (TBB). We performed an updated meta-analysis of the diagnostic yield of TBB for PLLs using RP-EBUS to generate recommendations for the development of the Korean Association of Lung Cancer guidelines.

MATERIALS AND METHODS

We systematically searched MEDLINE and EMBASE (from January 2013 to December 2022), and performed a meta-analysis using R software. The diagnostic yield was evaluated by dividing the number of successful diagnoses by the total lesion number. Subgroup analysis was performed to identify related factors.

RESULTS

Forty-one studies with a total of 13,133 PLLs were included. The pooled diagnostic yield of RP-EBUS was 0.72 (95% confidence interval [CI], 0.70 to 0.75). Significant heterogeneity was observed among studies (χ2=292.38, p < 0.01, I2=86.4%). In a subgroup analysis, there was a significant difference in diagnostic yield based on RP-EBUS findings (within, adjacent to, invisible), with a risk ratio of 1.45 (95% CI, 1.23 to 1.72) between within and adjacent to, 4.20 (95% CI, 1.89 to 9.32) between within and invisible, and 2.59 (95% CI, 1.32 to 5.01) between adjacent to and invisible. There was a significant difference in diagnostic yield based on lesion size, histologic diagnosis, computed tomography (CT) bronchus sign, lesion character, and location from the hilum. The overall complication rate of TBB with RP-EBUS was 6.8% (bleeding, 4.5%; pneumothorax, 1.4%).

CONCLUSION

Our study showed that TBB with RP-EBUS is an accurate diagnostic tool for PLLs with good safety profiles, especially for PLLs with within orientation on RP-EBUS or positive CT bronchus sign.

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.

Transbronchial Cryobiopsy Using the Ultrathin 1.1-mm Cryoprobe with Ultrathin Bronchoscopy under Radial Endobronchial Ultrasound Guidance for Diagnosis of Peripheral Pulmonary Lesions

INTRODUCTION

Today, the increasing number of incidentally detected peripheral pulmonary lesions (PPLs) within and outside lung cancer screening trials is a diagnostic challenge. This fact encourages further improvement of diagnostic procedures to increase the diagnostic yield of transbronchial biopsy, which has been shown to have a low complication rate. The purpose of this study was to evaluate the safety and feasibility of a new ultrathin 1.1 cryoprobe that can be placed through an ultrathin bronchoscope (UTB) using fluoroscopy and radial endobronchial ultrasonography (rEBUS) navigation for assessing PPLs.

METHODS

Thirty-five patients with PPL less than 4 cm in diameter were prospectively enrolled to receive transbronchial cryobiopsies (TBCBs) using the ultrathin 1.1-mm cryoprobe. Navigation to the PPL was accomplished with the UTB. Under rEBUS and fluoroscopy guidance up to 4 cryobiopsies were obtained. The sample sizes of the biopsies were compared to a historic collective derived from a 1.9-mm cryoprobe and standard forceps. The feasibility and safety of the procedure, the cumulative and overall diagnostic yield, and the cryobiopsy sizes were evaluated.

RESULTS

After detection with the rEBUS, TBCB was collected from 35 PPLs, establishing a diagnosis in 25 cases, corresponding to an overall diagnostic yield of 71.4%. There was no difference in diagnostic yield for PPL <20 mm or ≥20 mm. All cryobiopsies were representative with a mean tissue area of 11.9 ± 4.3 mm2, which was significantly larger compared to the historic collective (p = 0.003). Six mild and four moderate bleeding events and 1 case of pneumothorax were observed.

CONCLUSIONS

Using the ultrathin 1.1-mm cryoprobe combined with an UTB for rEBUS-guided TBCB of PPL is feasible and safe. This diagnostic approach improves bronchoscopic techniques for diagnosing peripheral lung lesions and may contribute to improve diagnosis of lung cancer even in small PPL.

Endobronchial Ultrasonography With Guide Sheath for the Diagnosis of Peripheral Pulmonary Lesions in Japan: A Literature Review

We evaluated the usefulness of endobronchial ultrasonography with guide sheath (EBUS-GS) for the diagnosis of peripheral pulmonary lesions (PPLs) in Japan. We searched the PubMed/Medline database using the keywords "EBUS guide sheath" for Japanese studies on EBUS-GS published between January 2004 and August 2023. We included 32 original articles that evaluated the diagnostic yield of EBUS-GS for PPLs. Case reports and conference abstracts were excluded due to limited information available for quality assessment. The diagnostic yield of EBUS-GS was 73.6% for 2996 malignant lesions, 65.4% for 752 ground-glass nodules, 59.4% for 414 benign lesions, 61.3% for 1114 lesions of size ≤2 cm, and 75.6% for 1246 lesions of size >2 cm; it was 69.4% for lesions located in the upper lobe (n=793), 71.9% for the middle lobe/lingula (n=121), and 62.5% for the lower lobe (n=334). None of the patients experienced severe complications. In this review, EBUS-GS is effective for the diagnosis of malignant and benign PPLs. A multimodality approach is needed to further enhance its diagnostic performance.

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.

Robotic versus Electromagnetic bronchoscopy for pulmonary LesIon AssessmeNT: the RELIANT pragmatic randomized trial

BACKGROUND

Robotic-assisted bronchoscopy has recently emerged as an alternative to electromagnetic navigational bronchoscopy for the evaluation of peripheral pulmonary lesions. While robotic-assisted bronchoscopy is proposed to have several advantages, such as an easier learning curve, it is unclear if it has comparable diagnostic utility as electromagnetic navigational bronchoscopy.

METHODS

Robotic versus Electromagnetic bronchoscopy for pulmonary LesIon AssessmeNT (RELIANT) is an investigator-initiated, single-center, open label, noninferiority, cluster randomized controlled trial conducted in two operating rooms at Vanderbilt University Medical Center. Each operating room (OR) is assigned to either robotic-assisted or electromagnetic navigational bronchoscopy each morning, with each OR day considered one cluster. All patients undergoing diagnostic bronchoscopy for evaluation of a peripheral pulmonary lesion in one of the two operating rooms are eligible. Schedulers, patients, and proceduralists are blinded to daily group allocations until randomization is revealed for each operating room each morning. The primary endpoint is the diagnostic yield defined as the proportion of cases yielding lesional tissue. Secondary and safety endpoints include procedure duration and procedural complications. Enrolment began on March 6, 2023, and will continue until 202 clusters have been accrued, with expected enrolment of approximately 400 patients by the time of completion in March of 2024.

DISCUSSION

RELIANT is a pragmatic randomized controlled trial that will compare the diagnostic yield of the two most commonly used bronchoscopic approaches for sampling peripheral pulmonary lesions. This will be the first known cluster randomized pragmatic trial in the interventional pulmonology field and the first randomized controlled trial of robotic-assisted bronchoscopy.

TRIAL REGISTRATION

ClinicalTrials.gov registration (NCT05705544) on January 30, 2023.

Transbronchial cryobiopsy for small peripheral pulmonary lesions using endobronchial ultrasonography and an ultrathin bronchoscope

BACKGROUND

Transbronchial biopsy using an ultrathin bronchoscope (UTB) has a high diagnostic yield for peripheral pulmonary lesions (PPLs). When combined with peripheral transbronchial needle aspiration (pTBNA), it improves the diagnostic yield of "adjacent to" radial endobronchial ultrasonography (rEBUS) findings. However, pTBNA is a complicated technique, and the specimen volume is often inadequate for diagnostic and multiplex analyses. Recently, transbronchial cryobiopsy (TBCB) using a 1.1-mm cryoprobe that could be inserted into an UTB has been available. We investigated whether TBCB combined with forceps biopsy using a 1.1-mm cryoprobe with an UTB improved the diagnostic yield of "adjacent to" lesions.

METHODS

The data of 66 consecutive patients who underwent TBCB and forceps biopsy using UTB (hemostasis using two-scope method) under rEBUS for small PPLs (≤30 mm) were retrospectively analyzed. The histological diagnosis rate using TBCB and forceps biopsy, TBCB alone, or forceps biopsy alone was compared between cases where the rEBUS probe was "within" and "adjacent to" lesions.

RESULTS

The diagnosis rate using TBCB and forceps biopsy was 81.8 % for all lesions ("within" vs. "adjacent to" cases: 88.4 % vs. 69.6 %; p = 0.093). The corresponding rate using TBCB alone was 80.3 % (86.0 % vs. 69.6 %; p = 0.19), and that using forceps biopsy alone was 62.1 % (74.4 % vs. 39.1 %; p = 0.008). Bleeding leading to discontinuation of the examination occurred in four (6.1 %) patients; however, in all cases, bleeding could be controlled endoscopically.

CONCLUSION

Forceps biopsy with TBCB during ultrathin bronchoscopy for small PPLs improved the diagnostic yield when the lesions were adjacent to the rEBUS probe.

Robotic navigational bronchoscopy in a thoracic surgery practice: Leveraging technology in the management of pulmonary nodules

Objectives

Robotic navigational bronchoscopy is increasingly used to improve diagnostic yield for pulmonary nodules compared with the 50% to 60% obtained by standard bronchoscopy; however, safety and efficacy data are limited to small series. The aim of this study was to evaluate diagnostic yield and clinical outcomes in a large multisurgeon single-center cohort.

Methods

All patients who underwent robotic navigational bronchoscopy and biopsy from September 2020 to October 2022 were identified from a prospective institutional registry. The primary outcome was diagnostic yield. The secondary outcome was diagnostic yield for molecular testing.

Results

A total of 503 nodules were biopsied during the study period. Median nodule size was 2.1 cm. Overall diagnostic yield was 87.9%. Factors associated with increased diagnostic yield were decreased time from date of planning computed tomography to procedure date (odds ratio, 0.98; 95% CI, 0.96-0.99; P = .04) and greater nodule size (odds ratio, 1.03; 95% CI, 1.01-1.07; P = .02) per 0.1-cm increment. Molecular analysis was sent in 101 patients and was sufficient in 90% of cases. Complications occurred in 22 (5%) patients, including 13 (3.1%) with pneumothoraxes (7 patients requiring a chest drain), and 5 (1.2%) patients had bleeding requiring intraprocedural bronchial intervention. A total of 41 patients were consented for biopsy and resection during a single anesthetic event. Four of these cases were stopped at robotic navigational bronchoscopy due to an alternative diagnosis. Mean length of stay was 3.4 ± 1.1 days. There were no major complications.

Conclusions

This study suggests robotic navigational bronchoscopy has a high diagnostic yield and obtains adequate tissue for molecular analysis critical for selection of targeted therapies. With careful patient selection robotic navigational bronchoscopy can be combined with surgery to treat lung cancer as a single procedure with low complication rates.

Ultrathin bronchoscopy for diagnosing peripheral pulmonary lesions

Bronchoscopes are continuously improving. Increasingly, thinner bronchoscopes with larger working channels and better imaging quality are becoming available for clinical use. Concurrently, useful ancillary devices have been developed, such as radial probe endobronchial ultrasound (rEBUS) and navigation devices. Randomized studies have demonstrated the diagnostic superiority of ultrathin bronchoscopy over thin bronchoscopy under rEBUS and virtual bronchoscopic navigation guidance for small, peripheral pulmonary lesions. Furthermore, biopsy needles and cryoprobes have been miniaturized and adapted to the working channel of the new ultrathin bronchoscopes. Multi-modality and multi-instrumental ultrathin bronchoscopy using such new technologies has facilitated high diagnostic yields.

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.

Close-to-lesion transbronchial biopsy: a novel technique to improve suitability of specimens for genetic testing in patients with peripheral pulmonary lesions

Bronchoscopy with radial-probe endobronchial ultrasound, a guide sheath, and electromagnetic navigation can improve the diagnostic yield of peripheral lung nodules. However, the suitability of specimens for genetic analysis remains unsatisfactory. We hypothesized that a transbronchial biopsy performed after closely approaching the bronchoscope tip to the lesion might provide more suitable specimens for genetic analysis. We enrolled 155 patients with peripheral pulmonary lesions who underwent bronchoscopy with a thin or ultrathin bronchoscope. Bronchoscopy was performed using virtual bronchoscopic navigation and radial-probe endobronchial ultrasound with a guide sheath. The bronchoscope tip was placed closer to the lesion during bronchoscopy to collect larger specimens with higher malignant cell content. The patients who underwent a close-to-lesion biopsy had higher rates of overall diagnostic yield, histopathological diagnostic yield, and specimen quality for genetic testing than those who did not. The significant determinants of the specimen's suitability were the close-to-lesion approach, within-the-lesion image, the use of standard 1.9-mm-forceps, and the number of cancer-cell-positive specimens. The significant predictors of the specimen's suitability for genetic analysis were close-to-lesion biopsy and the number of malignant cell-positive tissue samples. This study demonstrates that the close-to-lesion transbronchial biopsy significantly improves the suitability of bronchoscopic specimens for genetic analysis.

Robotic versus Electromagnetic Bronchoscopy for Pulmonary LesIon AssessmeNT: the RELIANT pragmatic randomized trial

Background

Robotic assisted bronchoscopy has recently emerged as an alternative to electromagnetic navigational bronchoscopy for the evaluation of peripheral pulmonary lesions. While robotic assisted bronchoscopy is proposed to have several advantages, such as an easier learning curve, it is unclear if it has comparable diagnostic utility as electromagnetic navigational bronchoscopy.

Methods

Robotic versus Electromagnetic Bronchoscopy for Pulmonary LesIon AssessmeNT (RELIANT) is an investigator-initiated, single-center, open label, noninferiority, cluster randomized controlled trial conducted in two operating rooms at Vanderbilt University Medical Center. Each operating room is assigned to either robotic assisted or electromagnetic navigational bronchoscopy each morning, with each OR day considered one cluster. All patients undergoing diagnostic bronchoscopy for evaluation of a peripheral pulmonary lesion in one of the two operating rooms are eligible. Schedulers, patients and proceduralists are blinded to daily group allocations until randomization is revealed for each operating room each morning. The primary endpoint is the diagnostic yield defined as the proportion of cases yielding lesional tissue. Secondary and safety endpoints include procedure duration and procedural complications. Enrolment began on March 6, 2023, and will continue until 202 clusters have been accrued, with expected enrolment of approximately 400 patients by the time of completion in March of 2024.

Discussion

RELIANT is a pragmatic randomized controlled trial that will compare the diagnostic yield of the two most commonly used bronchoscopic approaches for sampling peripheral pulmonary lesions. This will be the first known cluster randomized pragmatic trial in the interventional pulmonology field and the first randomized controlled trial of robotic assisted bronchoscopy.

Trial registration

ClinicalTrials.gov registration (NCT05705544) on January 30, 2023.

Diagnostic yield and the number of tumor cells of ultrathin bronchoscopy for peripheral lung lesions: A comparison with thin bronchoscopy

Ultrathin bronchoscopy has been reported to have a higher diagnostic yield than thin bronchoscopy for small peripheral lung lesions in transbronchial biopsy under radial endobronchial ultrasonography (EBUS). However, data comparing the number of tumor cells in non-small cell lung cancer (NSCLC) are limited. We retrospectively compared the number of NSCLC tumor cells in peripheral lung lesions obtained using an ultrathin bronchoscope and a thin bronchoscope with radial EBUS between April 2020 and October 2021. In all patients, we used virtual bronchoscopic navigation (VBN) software, and guide sheaths were used in thin bronchoscopy cases. A total of 175 patients were enrolled in this study. Ultrathin bronchoscopy cases (n = 69) had lesions with a smaller diameter that are more peripherally located compared to thin bronchoscopy cases (n = 106) (median, 25.0 vs. 26.5 mm, mean bronchial generations accessed by bronchoscopy; 4.4±1.2 vs. 3.8±1.0, respectively; p<0.010). There were no significant differences in the overall diagnostic yield (ultrathin vs. thin bronchoscopy cases, 68.1% vs. 72.6%, p = 0.610) or diagnostic yield in only lung cancer cases (78.6% vs. 78.5%, p = 1.000). In histologically NSCLC cases (n = 102), the maximum number of tumor cells per slide as the primary endpoint was similar (average, 307.6±246.7 vs. 328.7±314.9, p = 0.710). The success rate of the Oncomine™ analysis did not differ significantly (80.0% vs. 55.6%, p = 0.247). The yield of NSCLC tumor cells was not different between the samples obtained by the ultrathin bronchoscope and those obtained by the thin bronchoscope.

Single Setting Robotic Lung Nodule Diagnosis and Resection

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

Deep learning with test-time augmentation for radial endobronchial ultrasound image differentiation: a multicentre verification study

PURPOSE

Despite the importance of radial endobronchial ultrasound (rEBUS) in transbronchial biopsy, researchers have yet to apply artificial intelligence to the analysis of rEBUS images.

MATERIALS AND METHODS

This study developed a convolutional neural network (CNN) to differentiate between malignant and benign tumours in rEBUS images. This study retrospectively collected rEBUS images from medical centres in Taiwan, including 769 from National Taiwan University Hospital Hsin-Chu Branch, Hsinchu Hospital for model training (615 images) and internal validation (154 images) as well as 300 from National Taiwan University Hospital (NTUH-TPE) and 92 images were obtained from National Taiwan University Hospital Hsin-Chu Branch, Biomedical Park Hospital (NTUH-BIO) for external validation. Further assessments of the model were performed using image augmentation in the training phase and test-time augmentation (TTA).

RESULTS

Using the internal validation dataset, the results were as follows: area under the curve (AUC) (0.88 (95% CI 0.83 to 0.92)), sensitivity (0.80 (95% CI 0.73 to 0.88)), specificity (0.75 (95% CI 0.66 to 0.83)). Using the NTUH-TPE external validation dataset, the results were as follows: AUC (0.76 (95% CI 0.71 to 0.80)), sensitivity (0.58 (95% CI 0.50 to 0.65)), specificity (0.92 (95% CI 0.88 to 0.97)). Using the NTUH-BIO external validation dataset, the results were as follows: AUC (0.72 (95% CI 0.64 to 0.82)), sensitivity (0.71 (95% CI 0.55 to 0.86)), specificity (0.76 (95% CI 0.64 to 0.87)). After fine-tuning, the AUC values for the external validation cohorts were as follows: NTUH-TPE (0.78) and NTUH-BIO (0.82). Our findings also demonstrated the feasibility of the model in differentiating between lung cancer subtypes, as indicated by the following AUC values: adenocarcinoma (0.70; 95% CI 0.64 to 0.76), squamous cell carcinoma (0.64; 95% CI 0.54 to 0.74) and small cell lung cancer (0.52; 95% CI 0.32 to 0.72).

CONCLUSIONS

Our results demonstrate the feasibility of the proposed CNN-based algorithm in differentiating between malignant and benign lesions in rEBUS images.

Endobronchial ultrasound with a guide sheath during bronchoscopy for peripheral pulmonary lesions

INTRODUCTION

Radial probe endobronchial ultrasound (rEBUS) improves the diagnostic yield of peripheral pulmonary lesions (PPLs). A notable methodological limitation of rEBUS is that it does not provide real-time images during transbronchial biopsy (TBB) procedures. To overcome this limitation, a guide sheath (GS) method was developed.

AREAS COVERED

This review covers the procedures and complications of rEBUS-guided TBB with a GS (EGS method). We also present the data from key randomized controlled trials (RCTs) of the EGS method and summarize the usefulness of combining the EGS method with various techniques. Finally, we discuss in which situations EGS should be used.

EXPERT OPINION

A large RCT showed that the diagnostic yield of the EGS method for PPLs was significantly higher than that of rEBUS-guided TBB without a GS (non-GS method). However, since the EGS and non-GS methods each have their own advantages and disadvantages, they should be considered complementary and used flexibly in different cases. In some cases, a combination of the two may be an option. The appropriate combination of EGS with various techniques may enhance the diagnostic yield of PPLs and help prevent complications. The choice should be based on the location and texture of the target lesion, as well as operator skill, resource availability, safety, and accuracy.

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.

Ability of single anesthesia for combined robotic-assisted bronchoscopy and surgical lobectomy to reduce time between detection and treatment in stage I non-small cell lung cancer

Background

Background: Early identification, diagnosis, and treatment of lung cancer is associated with improved clinical outcomes. Robotic-assisted bronchoscopy improves the ability to diagnose early stage lung malignancies and, when combined with robotic-assisted lobectomy under single anesthesia, could reduce time from identification to intervention in early stage lung cancer in a select patient population.

Methods

Methods: A retrospective case-control single-center study compared patients with radiographic stage I non-small cell carcinoma (NSCCA) undergoing robotic navigational bronchoscopy and surgical resection (N = 22) with historical controls (N = 63). The primary outcome was time from initial radiographic identification of a pulmonary nodule to therapeutic intervention. Secondary outcomes included times between identification to biopsy, biopsy to surgery, and procedural complications.

Results

Results: Patients with suspected stage I NSCCA who received single anesthesia for diagnosis and intervention with robotic-assisted bronchoscopy and robotic-assisted lobectomy had shorter times between identification of a pulmonary nodule and intervention compared to controls (65 vs 116 days, P = 0.005). Cases had lower rates of complications (0% vs 5%) and shorter hospitalizations after surgery (3.6 vs 6.2 days, P = 0.017).

Conclusion

Conclusion: Our findings support that implementing a multidisciplinary thoracic oncology team and single-anesthesia biopsy-to-surgery approach in management of stage I NSCCA significantly reduced times from identification to intervention, biopsy to intervention, and length of hospital stays in management of lung cancer.

Advances in Surgical Techniques for Lung Cancer

Thoracic surgery for non-small cell lung cancer has evolved tremendously in the past two decades. Improvements have come on multiples fronts and include a transition to minimally invasive techniques, an incorporation of neoadjuvant treatment, and a greater utilization of sublobar resection. These advances have reduced the morbidity of thoracic surgery, while maintaining or improving long-term survival. This review highlights major advances in the surgical techniques of lung cancer and the keys to optimizing outcomes from a surgical perspective.

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.

Computed Tomography Bronchus Sign Subclassification during Radial Endobronchial Ultrasound-Guided Transbronchial Biopsy: A Retrospective Analysis

The presence of computed tomography bronchus sign (CT-BS) substantially increases the diagnostic yield of peripheral pulmonary lesions. However, the clinical significance of subdividing CT-BS remains controversial. We classified bronchus types on CT into six subtypes (CT-BS group I: types Ia–Ic with the bronchus connected within the lesion, group II: types IIa–IIc without connection) to clarify the differences in their characteristics and investigate the factors associated with diagnosis during radial endobronchial ultrasound (rEBUS)-guided bronchoscopy. In total, 1021 cases were analyzed. Our findings in diagnostic yields were that in CT-BS group I, penetrating type Ic was inferior to obstructed type Ia and narrowing type Ib (59.0% vs. 80.0% and 76.3%, p < 0.001, p = 0.004); in CT-BS group II, compressed type IIa showed no difference when compared with invisible type IIb and uninvolved type IIc (IIa: 52.8% vs. IIb: 46.3% and IIc: 35.7%, p = 0.253). Multivariable analysis revealed that bronchus type (types Ia and Ib vs. Ic) was a significant independent predictor of successful diagnosis in CT-BS group I (odds ratio, 1.78; 95% confidence interval, 1.04–3.05; p = 0.035), along with known factors such as rEBUS visualization. CT-BS subclassification may provide useful information regarding the bronchoscopic technique to facilitate accurate diagnosis.

Electromagnetic Navigation Bronchoscopy Versus Radial Endobronchial Ultrasound for Diagnosing Lung Cancer: A Propensity Score-Matched Analysis

INTRODUCTION

Electromagnetic navigation bronchoscopy (ENB) and radial endobronchial ultrasound (R-EBUS) are advanced imaging-guided bronchoscopy techniques for diagnosing pulmonary lesions. This study aimed to determine the comparative diagnostic yield of sole ENB and R-EBUS under moderate sedation.

METHODS

We investigated 288 patients who underwent sole ENB (n=157) or sole R-EBUS (n=131) under moderate sedation for pulmonary lesion biopsy between January 2017 and April 2022. After a 1:1 propensity score-matching to control for pre-procedural factors, the diagnostic yield, sensitivity for malignancy, and procedure-related complications between both techniques were compared.

RESULTS

The matching resulted in 105 pairs/procedure for analyses with balanced clinical and radiological characteristics. The overall diagnostic yield was significantly higher for ENB than for R-EBUS (83.8% vs. 70.5%, p=0.021). ENB demonstrated a significantly higher diagnostic yield than R-EBUS among those with lesions>20mm in size (85.2% vs. 72.3%, p=0.034), radiologically solid lesions (86.7% vs. 72.7%, p=0.015), and lesions with a class 2 bronchus sign (91.2% vs. 72.3%, p=0.002), respectively. The sensitivity for malignancy was also higher for ENB than for R-EBUS (81.3% vs. 55.1%, p<0.001). After adjusting for clinical/radiological factors in the unmatched cohort, using ENB over R-EBUS was significantly associated with a higher diagnostic yield (odd ratio=3.45, 95% confidence interval=1.75-6.82). Complication rates for pneumothorax did not significantly differ between ENB and R-EBUS.

CONCLUSION

ENB demonstrated a higher diagnostic yield than R-EBUS under moderate sedation for diagnosing pulmonary lesions, with similar and generally low complication rates. Our data indicate the superiority of ENB over R-EBUS in a least-invasive setting.

The additional diagnostic value of virtual bronchoscopy navigation in patients with pulmonary nodules - The NAVIGATOR study

BACKGROUND

The number of solitary pulmonary nodules to be evaluated is expected to increase and therefore we need to improve diagnostic and therapeutic tools to approach these nodules. To prevent patients from futile invasive procedures and receiving treatment without histological confirmation of cancer, we evaluated the value of virtual bronchoscopy navigation to obtain a diagnosis of the solitary pulmonary nodule in a real-world clinical setting.

METHODS

In the NAVIGATOR single center, prospective, observational cohort study patients underwent a virtual bronchoscopy navigation procedure with or without guide sheet tunnelling to assess a solitary pulmonary nodule. Nodules were considered not accessible if a diagnosis could not be obtained by either by CT-guided transthoracic biopsy or conventional bronchoscopy.

RESULTS

Between February 2021 and January 2022 35 patients underwent the virtual bronchoscopy navigation procedure. The overall diagnostic yield was 77% and was dependent on size of the nodule and chosen path, with highest yield in lesions with an airway path. Adverse events were few and manageable.

CONCLUSION

Virtual bronchoscopy navigation with or without sheet tunnelling is a new technique with a good diagnostic yield, also in patients in whom previously performed procedures failed to establish a diagnosis and/or alternative procedures are considered not feasible based on expected yield and/or safety. Preventing futile or more invasive procedures like surgery or transthoracic punctures with a higher complication rate is beneficial for patients, and allowed treatment adaptation in two-third of the analyzed patient population.

Solitary Lung Nodule: CT-Guided Transthoracic Biopsy vs Transbronchial Biopsy With Endobronchial Ultrasound and Flexible Bronchoscope, a Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Transbronchial lung biopsy with radial endobronchial ultrasound (rEBUS-TBB) and Computed tomography (CT) scan-guided transthoracic biopsy (CT-TTB) are commonly used to investigate peripheral lung nodules but high-quality data are still not clear about the diagnostic and safety profile comparison of these two modalities.

METHOD

We included all randomized controlled trials (RCT) comparing rEBUS-TBB with a flexible bronchoscope and CT-TTB for solitary lung nodules. Two reviewers extracted data independently on diagnostic performance and complication rates.

RESULTS

170 studies were screened, 4 RCT with a total of 325 patients were included. CT-TTB had a higher diagnostic yield than rEBUS-TBB (83.45% vs 68.82%, risk difference - 0.15, 95% CI, [- 0.24, - 0.05]), especially for lesion size 1-2 cm (83% vs 50%, risk difference - 0.33, 95% CI, [- 0.51, - 0.14]). For malignant diseases, rEBUS-TBB had a diagnostic yield of 75.75% vs 87.7% of CT-TTB. rEBUS-TBB had a significant better safety profile with lower risks of pneumothorax (2.87% vs 21.43%, OR = 0.12, 95% CI [0.05-0.32]) and combined outcomes of hospital admission, hemorrhage, and pneumothorax (8.62% vs 31.81%, OR 0.21, 95% CI, [0.11-0.40]). Factors increasing diagnostic yield of rEBUS were lesion size and localization of the probe but not the distance to the chest wall and hilum.

CONCLUSION

CT-TTB had a higher diagnostic yield than rEBUS-TBB in diagnosing peripheral lung nodules, particularly for lesions from 1 to 2 cm. However, rEBUS-TBB was significantly safer with five to eight times less risk of pneumothorax and composite complications of hospital admission, hemorrhage, and pneumothorax. The results of this study only apply to flexible bronchoscopy with radial ebus without navigational technologies. More data are needed for a comparison between CT-TTB with rEBUS-TBB combined with advanced navigational modalities.

Ultrathin bronchoscopic cryobiopsy of peripheral pulmonary lesions

BACKGROUND AND OBJECTIVE

Ultrathin bronchoscopy aids in the diagnosis of peripheral pulmonary lesions. However, both the working channel and the specimens are small. A 1.1-mm ultrathin cryoprobe that can enter the working channel of the ultrathin bronchoscope is now available, which may overcome the limitations of small specimen size. The aim of this study was to evaluate the feasibility, efficacy and safety of ultrathin bronchoscopic cryobiopsy using an ultrathin cryoprobe for diagnosing peripheral pulmonary lesions.

METHODS

Patients with peripheral pulmonary lesions ≤30 mm in diameter were prospectively enrolled in the study. All patients underwent forceps biopsy followed by cryobiopsy using a 3.0-mm ultrathin bronchoscope under radial probe endobronchial ultrasound guidance, virtual bronchoscopic navigation and fluoroscopic guidance. The primary endpoint was the feasibility of cryobiopsy.

RESULTS

In total, 50 patients with peripheral pulmonary lesions were enrolled in the study; the median longest diameter on computed tomography was 17.9 mm. Cryobiopsy was performed successfully in 49 patients (98%). Forceps biopsy, cryobiopsy and the combination of these two methods provided a specific diagnosis in 54% (27/50), 62% (31/50) and 74% (37/50) of patients, respectively. The median size of specimens obtained via cryobiopsy was significantly larger than the median size obtained via forceps biopsy (7.0 vs. 1.3 mm² , respectively, p < 0.001). Mild bleeding during cryobiopsy occurred in 47 patients (94%). No moderate/severe bleeding or pneumothorax occurred.

CONCLUSION

Ultrathin bronchoscopic cryobiopsy is feasible, effective and sufficiently safe for the diagnosis of peripheral pulmonary lesions.

Value of adding ultrathin bronchoscopy to thin bronchoscopy for peripheral pulmonary lesions: A multicentre prospective study

BACKGROUND AND OBJECTIVE

The diagnostic yield of thin bronchoscopy with radial probe endobronchial ultrasound (rEBUS) of peripheral pulmonary lesions into which the rEBUS probe cannot be inserted is unsatisfactory. In such cases, adding ultrathin bronchoscopy may be an option. We evaluated the efficacy of sequential ultrathin bronchoscopy for peripheral pulmonary lesions into which the rEBUS probe could not be inserted during thin bronchoscopy.

METHODS

In this multicentre prospective study, patients with peripheral pulmonary lesions ≤30 mm in diameter underwent rEBUS-guided transbronchial biopsy using a 4.0 mm diameter thin bronchoscope. In patients with lesions into which a rEBUS probe could not be inserted using that bronchoscope, bronchoscopy using a 3.0 mm diameter ultrathin bronchoscope was performed.

RESULTS

A total of 342 patients were enrolled and 340 were analysed. Among them, 87 patients with lesions of a median longest diameter of 17.5 mm underwent thin bronchoscopy followed by ultrathin bronchoscopy. Of the 87 patients, the rEBUS probe was successfully inserted into the lesions via the ultrathin bronchoscope in 50 patients (57.5%). Of the 87 patients, the diagnostic yields of thin bronchoscopy and ultrathin bronchoscopy were 12.6% (11 of 87) and 41.4% (36 of 87), respectively (p < 0.001).

CONCLUSION

Ultrathin bronchoscopy affords a higher diagnostic yield for lesions into which a rEBUS probe cannot be inserted via a thin bronchoscope.

Inheritance and innovation of the diagnosis of peripheral pulmonary lesions

As the leading cause of cancer-related deaths worldwide, early detection and diagnosis are crucial to reduce the mortality of lung cancer. To date, the diagnosis of the peripheral pulmonary lesions (PPLs) remains a major unmet clinical need. The urgency of diagnosing PPLs has driven a series of development of the advanced bronchoscopy-guided techniques in the past decades, such as radial probe-endobronchial ultrasonography (RP-EBUS), virtual bronchoscopy navigation (VBN), electromagnetic navigation bronchoscopy (ENB), bronchoscopic transparenchymal nodule access (BTPNA), and robotic-assisted bronchoscopy. However, these techniques also have their own limitations. In this review, we would like to introduce the development of diagnostic techniques for PPLs, with a special focus on biopsy approaches and advanced guided bronchoscopy techniques by discussing their advantages, limitations, and future prospects.

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.

Proposal of a novel pipeline involving precise bronchoscopy of distal peripheral pulmonary lesions for genetic testing

Next-generation sequencing (NGS) has become increasingly more important for lung cancer management. We now expect biopsies to be sensitive, safe, and yielding sufficient samples for NGS. In this study, we propose ultraselective biopsy (USB) with sample volume adjustment (SVA) as a novel method that integrates an ultrathin bronchoscope, radial probe endobronchial ultrasound, and the direct oblique method for ultraselective navigation, and adjustment of sample volume for NGS. Our purpose was to estimate the diagnostic potential and the applicability of USB-SVA for amplicon-based NGS analysis. The diagnostic yield of bronchoscopy in forty-nine patients with malignant peripheral pulmonary lesions (PPLs) was retrospectively analyzed, and amplicon-based NGS analysis was performed on samples from some patients using USB. The diagnostic yields of distal PPLs in the USB group were significantly higher than those in the non-USB group (90.5% vs. 50%, respectively, p = 0.015). The extracted amounts of nucleic acids were at least five times the minimum requirement and the sequence quality met the criteria for the Oncomine™ Target Test. Only the tumor cell content of some samples was insufficient. The feasibility of the pipeline for USB, SVA, and amplicon-based NGS in distal PPLs was demonstrated.

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.

Virtual bronchoscopic navigation and endobronchial ultrasound with a guide sheath without fluoroscopy for diagnosing peripheral pulmonary lesions with a bronchus leading to or adjacent to the lesion: A randomized non‐inferiority trial

BACKGROUND AND OBJECTIVE

Transbronchial sampling of peripheral pulmonary lesions (PPLs) is routinely performed under fluoroscopy. However, advanced ancillary techniques have become available, such as virtual bronchoscopic navigation (VBN) and radial endobronchial ultrasound with a guide sheath (rEBUS-GS). This study was performed to determine whether the diagnostic utility of VBN and rEBUS with a GS is similar with or without fluoroscopy.

METHODS

This multicenter non-inferiority trial randomized patients to a VBN-rEBUS-GS with or without fluoroscopy group at three centres. The primary endpoint was the diagnostic yield. The secondary endpoints were the time for rEBUS, GS, and the total operation. Complications were also recorded.

RESULTS

Four hundred and ninety-six subjects were assessed and 426 subjects were included in the analysis (212 in non-fluoroscopy-guided-group and 214 in fluoroscopy-guided-group). The diagnostic yield in the non-fluoroscopy-guided-group (84.0%) was not inferior to that in the fluoroscopy-guided-group (84.6%), with a diagnostic difference of -0.6% (95% CI: -6.4%, 5.2%). Multivariable analysis confirmed that bronchus sign and lesion nature were valuable diagnostic predictors in non-fluoroscopy-guided-group. The non-fluoroscopy-guided-group had shorter rEBUS, GS, and total operation time. No severe complications occurred in either group.

CONCLUSION

Transbronchial diagnosis of PPLs suspicious of malignancy and presence of a bronchus leading to or adjacent to lesions using VBN-rEBUS-GS without fluoroscopy is a safe and effective method that is non-inferior to VBN-rEBUS-GS with fluoroscopy. Bronchus leading to lesions and malignant nature are associated with high diagnostic yield in VBN-rEBUS-GS without fluoroscopy for the diagnosis of PPLs.

Diagnostic Yield and Safety of CP-EBUS-TBNA and RP-EBUS-TBLB under Moderate Sedation: A Single-Center Retrospective Audit

Convex probe endobronchial ultrasound transbronchial needle aspirations (CP-EBUS-TBNAs) and radial probe endobronchial ultrasound transbronchial lung biopsies (RP-EBUS-TBLBs) can be performed under moderate sedation or general anesthesia. Moderate sedation is more convenient, however patient discomfort may result in inadequate tissue sampling. General anesthesia ensures better patient cooperation but requires more logistics and also carries sedation risks. We aim to describe the diagnostic yield and safety of CP-EBUS-TBNAs and RP-EBUS-TBLBs when performed under moderate sedation at our center. All patients who underwent CP-EBUS-TBNA and/or RP-EBUS-TBLB under moderate sedation, between January 2015 and May 2017, were reviewed. Primary outcomes were defined in regard to the diagnostic yield and safety profile. A total of 336 CP-EBUS-TBNAs and 190 RP-EBUS-TBLBs were performed between January 2015 and May 2017. The mean sedation doses used were 50 mcg of intravenous fentanyl and 2.5 mg of intravenous midazolam. The diagnostic yield of the CP-EBUS-TBNAs and RP-EBUS-TBLBs were 62.5% and 71.6%, respectively. Complication rates were low with: transient bleeding 11.9%, transient hypoxia 0.5%, and pneumothorax 0.1%. None required escalation of care, post procedure. Performing CP-EBUS-TBNAs and RP-EBUS-TBLBs under moderate sedation is safe and provides good diagnostic yield. These procedures should, therefore, be considered as first-line sampling techniques.

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.

Hierarchical clock-scale hand-drawn mapping as a simple method for bronchoscopic navigation in peripheral pulmonary nodule

Background

A feasible and economical bronchoscopic navigation method in guiding peripheral pulmonary nodule biopsy is lacking.

Objective

To investigate the utility of hierarchical clock-scale hand-drawn mapping for bronchoscopic navigation in peripheral pulmonary nodules.

Methods

We developed a hierarchical clock-scale hand-drawn mapping for bronchoscopic navigation in peripheral pulmonary nodules. Patients with peripheral pulmonary nodules were recruited and assigned to two groups in this retrospective study, subjects in VBN group received conventional bronchoscopy in conjunction with virtual bronchoscopic navigation (VBN) and radial probe endobronchial ultrasound (RP-EBUS) for biopsy (VBN group), while HBN group underwent ultrathin bronchoscopy and RP-EBUS under the guidance of hand-drawn bronchoscopic navigation (HBN). The demographic characteristics, procedural time, operating cost and diagnostic yield were compared between these two groups.

Results

Forty-eight patients with peripheral pulmonary nodule were enrolled in HBN group, while 42 in VBN group. There were no significant differences between VBN and HBN groups in terms of age, gender, lesion size, location and radiographic type. The time of planning pathway (1.32 vs. 9.79 min, P < 0.001) and total operation (23.63 vs. 28.02 min, P = 0.002), as well as operating cost (758.31 ± 125.21 vs.1327.70 ± 116.25 USD, P < 0.001) were markedly less in HBN group, compared with those in VBN group. The pathological diagnostic efficiency of benign and malignant disease in HBN group appeared similar with those in VBN group, irrespective of the size of pulmonary lesion (larger or smaller than 20 mm). The total diagnostic yield of HBN had no marked difference from that of VBN (75.00% vs. 61.90%, P = 0.25).

Conclusions

Hierarchical clock-scale hand-drawn mapping for bronchoscopic navigation could serve as a feasible and economical method for guiding peripheral pulmonary nodule biopsy, providing a comparable diagnostic yield in comparison with virtual bronchoscopic navigation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02160-0.

Combined procedure with radial probe and convex probe endobronchial ultrasound

Background

Concurrent bronchoscopy using radial probe and convex endobronchial ultrasound (RP‐ and CP‐EBUS) is used to simultaneously evaluate both peripheral lung lesions for the histological diagnosis of the primary tumor and mediastinal lymph nodes for mediastinal staging. So far, little is known about the combined procedure with RP‐ and CP‐EBUS.

Methods

Between January 2020 and March 2021, the bronchoscopy database was reviewed to identify the clinical outcomes of the combined procedure with RP‐ and CP‐EBUS. Patients who underwent transbronchial biopsy using RP‐EBUS alone were classified as the RP‐EBUS group, while those who underwent a combined procedure with RP‐ and CP‐EBUS were classified as the combination group.

Results

The overall diagnostic yield of the bronchoscopic procedure in the combination group was significantly higher than the RP‐EBUS group (90.7% vs. 70.0%, p < 0.001). CP‐EBUS increased the diagnostic yield of the bronchoscopic procedure in the combination group by 9.3%. Although the mean procedure time was significantly longer, and the mean doses of midazolam and fentanyl were significantly higher in the combination group (p < 0.001), there were no differences in the overall complication rates between the two study groups (1.4% and 1.0% for the RP‐EBUS and combination groups, respectively, p = 0.766).

Conclusions

Combined bronchoscopy using RP‐ and CP‐EBUS is feasible and safe. In addition to mediastinal staging, CP‐EBUS increased the overall diagnostic yield of the bronchoscopic procedure by 9.3%.