Transesophageal Ultrasonography for Lung Cancer Staging: Learning Curves of Pulmonologists

Added value of EUS-B-FNA to bronchoscopy and EBUS-TBNA in diagnosing and staging of lung cancer

Background

Bronchoscopy and EBUS are standard procedures in lung cancer work-up but have low diagnostic yield in lesions outside the central airways and hilar/mediastinal lymph nodes. Growing evidence on introducing the EBUS endoscope into the oesophagus (EUS-B) in the same session as bronchoscopy/EBUS gives access to new anatomical areas that can be safely biopsied.

Objective

To summarize the current evidence of the added value of EUS-B-FNA to bronchoscopy and EBUS-TBNA in lung cancer work-up.

Methods

A narrative review.

Results

Few randomized trials or prospective studies are available. Prospective studies show that add-on EUS-B-FNA increases diagnostic yield when sampling abnormal mediastinal lymph nodes, para-oesophageal lung and left adrenal gland. A large retrospective series on EUS-B-FNA from retroperitoneal lymph nodes suggests high diagnostic yield without safety concerns, as do casuistic reports on EUS-B-FNA from mediastinal pleural thickening, pancreatic lesions, ascites fluid and pericardial effusions. No study has systematically assessed both diagnostic yield, safety, patient reported outcomes, adverse events and costs.

Conclusion

The diagnostic value of add-on EUS-B to standard bronchoscopy and EBUS in lung cancer work-up appears very promising without safety concerns, giving the pulmonologist access to a variety of sites out of reach with other minimally invasive techniques. Little is known on patient-reported outcomes and costs. Future and prospective research should focus on effectiveness aspects to clarify whether overall benefits of add-on EUS-B sufficiently exceed overall downsides.

Controversies in endobronchial ultrasound

Endobronchial ultrasound (EBUS) is a minimally invasive highly accurate and safe endoscopic technique for the evaluation of mediastinal lymphadenopathy and mediastinal masses including centrally located lung tumors. The combination of transbronchial and transoesophageal tissue sampling has improved lung cancer staging, reducing the need for more invasive and surgical diagnostic procedures. Despite the high level of evidence regarding EBUS use in the aforementioned situations, there are still challenges and controversial issues such as follows: Should informed consent for EBUS and flexible bronchoscopy be different? Is EBUS able to replace standard bronchoscopy in patients with suspected lung cancer? Which is the best position, screen orientation, route of intubation, and sedation/anesthesia to perform EBUS? Is it advisable to use a balloon in all procedures? How should the operator acquire skills and how should competence be ensured? This Pro-Con article aims to address these open questions.

Developing a simulation-based training curriculum in transesophageal ultrasound with the use of the endobronchial ultrasound-endoscope

There is an increasing need to focus on how best to train respiratory physicians to perform EUS with bronchoscope-guided fine-needle aspiration biopsy (EUS-B-FNA). At current, training is mostly performed in the clinical environment under expert supervision; however, the advent of simulation-based education now provides a low-risk setting for novice trainees to learn and practice basic endosonography skills from identifying and understanding normal anatomy as well as pathology, maneuvering of endoscope, interpretation of images, and mastering of sampling techniques. In this descriptive educational paper, we used a six-step approach as a framework to describe the development of a structured training program combining EUS-B-FNA with the already well-established certification training program in endobronchial ultrasound transbronchial needle aspiration. This comprehensive training curriculum includes a theoretical course to achieve foundational knowledge, followed by simulation-based training until mastery standards are met, and supervised clinical apprenticeship. All steps should end with an objective assessment to achieve certification. This systematic development will hopefully encourage endosonography leaders and educators to collaborate and implement an evidence-based comprehensive endosonography curriculum that aims to provide the trainee with the essential EUS-B competencies to ensure that lung cancer patients are diagnosed and staged correctly.

Transitioning to Combined EBUS EUS-B FNA for Experienced EBUS Bronchoscopist

Endobronchial ultrasound (EBUS) combined with trans-esophageal endoscopic ultrasound bronchoscope guided fine need aspirate (EUS-B FNA) of mediastinal lymph nodes is an established procedure for diagnosis. The main barrier to a combined EBUS EUS-B FNA approach is availability of trained and accredited pulmonologist who can perform procedure safely and confidently. To address this gap, we undertook a training program for experienced EBUS bronchoscopists to train, learn, and incorporate combined EBUS EUS-B FNA into their procedural practice. Thirty-two patients were selected based on CT and or PET findings. Four experienced bronchoscopists participated by reading through learning material, observing 5 cases before performing EUS-B FNA under direct supervision. Forty-one lymph nodes and 6 non-nodal lesions were sampled. EUSAT assessment was performed by supervisor. Learning curves were derived from assessment scores. We observed that learning curve tends to plateau when participant can perform 3 or more consecutive cases with EUSAT score above 50. There were no complications. Our experience suggests that there is relative ease in transition to combined EBUS EUS-B TBNA procedures for mediastinal lymphadenopathy and lung cancer diagnosis and staging for experienced bronchoscopist using a program which incorporates direct supervision, EUSAT assessment, and extension of EUS B FNA training into daily real-world practice.

Diagnosis and staging of lung cancer with the use of one single echoendoscope in both the trachea and the esophagus: A practical guide

Accurate staging of non-small cell lung cancer (NSCLC) is crucial for allocation to surgical, medical or multimodal treatment. EUS and endobronchial ultrasound (EBUS) have gained ground in the diagnosis and staging of lung cancer in addition to radiological imaging (e.g., computed tomography, fluoroscopy, and magnetic resonance imaging), nuclear medicine techniques (e.g. positron emission tomography, PET), combined techniques (e.g., fluorodesoxyglucosepositron emission tomography scanning), and sonographic imaging including conventional transcutaneous mediastinal and lung ultrasound. By using one single echoendoscope in both the trachea and the esophagus, surgical staging procedures (e.g. mediastinoscopy and video assisted thoracoscopy) can be avoided in a considerable proportion of patients with NSCLC.

Transoesophageal endobronchial ultrasound-guided needle aspiration (EUS-B-NA) for poorly accessible thoracic lesions: a case series

Endobronchial ultrasound (EBUS) has long been a common diagnostic tool used in the diagnosis of pulmonary pathologies. In the last decade, increased interest has been shown in its usage via the oesophagus for sampling lesions inaccessible via the airways. We describe three cases in which we used this modality to biopsy lesions not visualised via conventional EBUS and which would be too risky to be attempted via a CT-guided biopsy with a high likelihood of complications. More focused education on using EBUS via the oesophagus for respiratory trainees could greatly improve overall clinical practice. It improves the diagnostic yield of lesions and prevents subsequent referral to gastrointestinal colleagues which may delay diagnosis especially during the COVID-19 pandemic as was the case in our patient cohort where services are already limited. EBUS, due to its smaller size, is less irritant to the upper airways and requires less sedation than endoscopic ultrasound (EUS) scopes. It is also shorter than an EUS scope improving manoeuvrability. Each of our cases resulted in early histological diagnosis and subsequent appropriate treatment.

Integration of Bronchoscopic Transesophageal Ultrasound Examination of the Left Adrenal Gland into Routine Lung Cancer Staging Workup: A Prospective Trial

BACKGROUND

Endobronchial ultrasound (EBUS) with transbronchial needle aspiration increases the diagnostic yield of lung cancer staging. The left adrenal gland (LAG) is a common site for lung cancer metastasis. The modality of transesophageal examination with an EBUS bronchoscope (EUS-B) routinely for LAG has not been assessed.

OBJECTIVE

The aim of this study was to prospectively assess if evaluation and tissue sampling of the LAG could routinely be implemented in an EBUS procedure.

METHODS

Patients referred for EBUS between March and August 2017 had assessment of the LAG via EUS-B. Fine-needle aspiration (FNA) was performed in cases with a suspicious LAG. The detection rate, procedure time, and learning curve of four experienced EBUS-bronchoscopists was assessed, plus the diagnostic accuracy and complication rate of FNA.

RESULTS

In total, 313 consecutive patients were included. The overall LAG detection rate was 87.5%. After the initial learning curve, the detection rate for all four bronchoscopists was >93%. The detection rate did not correlate with any patient characteristics. EUS-B-FNA revealed nine LAG metastases, with a sensitivity, specificity, and accuracy of 75%, 100%, and 99%, respectively. The mean EUS-B operation time was 194.4 s, with 594.8 s for FNA. There were no FNA-associated complications.

CONCLUSIONS

Evaluation of the LAG with EUS-B could routinely be included in an EBUS procedure if necessary. A high detection rate can be achieved after an initial learning period. FNA of the LAG was feasible and safe. EUS-B of the LAG could be integrated into the usual EBUS/EUS-B procedure in lung cancer staging workup.

Trans-esophageal endobronchial ultrasound-guided needle aspiration (EUS-B-NA): A road map for the chest physician

The endobronchial ultrasound (EBUS) scope has been increasingly used in the gastrointestinal tract (EUS-B). Scientific data proves its efficacy and safety to provide a complete lung cancer staging, when combined with EBUS-TBNA, and in the diagnosis of para-esophageal lesions. There are multiple barriers to start performing EUS-B but probably the most important ones are related to knowledge and training, so new operators should follow a structured training curriculum. This review aims to reflect the best current knowledge regarding EUS-B and provide a road map to assist those who are incorporating the technique into their clinical practice.

Endoscopic ultrasound fine-needle aspiration by experienced pulmonologists: a cusum analysis

Endobronchial ultrasound transbronchial needle aspiration (EBUS TBNA) is an established, minimally invasive way to sample intrathoracic abnormalities. The EBUS scope can be passed into the oesophagus to perform endoscopic ultrasound with bronchoscope-guided fine-needle aspiration (EUS-B-FNA). In cases of suspected lung cancer, a combination of the two techniques is now recommended by consensus guidelines. EBUS TBNA is usually performed by pulmonologists; however, the learning curve for EUS-B-FNA, which may be performed during the same procedure, has not been described.A multicentre, observational Australian study, using prospectively collected data from three experienced pulmonologists was conducted. Cumulative sum (cusum) analysis was used to generate visual learning curves.A total of 152 target lesions were sampled in 137 patients, with an overall sensitivity for malignancy of 94.8%. The sensitivity for malignant lesions outside of the 2009 International Association for the Study of Lung Cancer lymph node map (largely intraparenchymal lesions) was 92.9%. All three operators were competent by conventional cusum criteria. There was one case of pneumothorax, and no episodes of mediastinitis or oesophageal perforation were observed.Our data suggest that experienced pulmonologists can safely and accurately perform EUS-B-FNA, with a high diagnostic sensitivity for both lymph node and non-nodal lesions.

Pulmonologist-performed transoesophageal sampling for lung cancer staging using an endobronchial ultrasound video-bronchoscope: an Australian experience

BACKGROUND

Transoesophageal endobronchial ultrasound (EBUS) video-bronchoscope insertion provides pulmonologists access to conduct endoscopic fine-needle aspiration (EUS-B-FNA) of mediastinal lymph node (LN) lesions and also assist in lung cancer staging by sampling left adrenal gland (LAG) lesions. Limited literature has described additional diagnostic value whilst maintaining patient safety. To elicit whether combining endoscopic transoesophageal fine-needle aspiration using convex probe bronchoscope (EUS-B-FNA) and EBUS bronchoscopy enhances the diagnostic yield of mediastinal nodal staging in lung cancer, whilst maintaining safety.

METHODS

All eligible patients with paraoesophageal lesions on thoracic computed tomography (CT) underwent pulmonologist-performed EUS-B-FNA at two tertiary centres and were included in this prospective observational cohort study.

RESULTS

EUS-B-FNA sampling was performed at 69 mediastinal LN lesion sites, including 17 sites inaccessible to bronchoscopic sampling. Four LAG lesions were sampled via EUS-B-FNA. There were no complications. EBUS-TBNA was augmented by EUS-B-FNA because of accessibility of sampling lesions otherwise unamenable bronchoscopically, thereby increasing diagnostic utility. Diagnostic sensitivity of EUS-B-FNA for malignancy in mediastinal LN lesions was 88% (51 of 58). For mediastinal LN lesions not amenable to EBUS-TBNA, the sensitivity for diagnosis of malignancy via EUS-B-FNA was 88% (15 of 17). Diagnostic sensitivity of EUS-B-FNA for malignancy in LAG lesions was 50% (2 of 4).

CONCLUSION

EUS-B-FNA is a precise and safe approach in the evaluation and staging of lung cancer when performed by a pulmonologist. It complements and increases the diagnostic utility of EBUS-TBNA by further coverage of mediastinal LN stations and access to LAG lesions.

Training and certification in endobronchial ultrasound-guided transbronchial needle aspiration

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) plays a key role in the staging of lung cancer, which is crucial for allocation to surgical treatment. EBUS-TBNA is a complicated procedure and simulation-based training is helpful in the first part of the long learning curve prior to performing the procedure on actual patients. New trainees should follow a structured training programme consisting of training on simulators to proficiency as assessed with a validated test followed by supervised practice on patients. The simulation-based training is superior to the traditional apprenticeship model and is recommended in the newest guidelines. EBUS-TBNA and oesophageal ultrasound-guided fine needle aspiration (EUS-FNA or EUS-B-FNA) are complementary to each other and the combined techniques are superior to either technique alone. It is logical to learn and to perform the two techniques in combination, however, for lung cancer staging solely EBUS-TBNA simulators exist, but hopefully in the future simulation-based training in EUS will be possible.

Pulmonologist-Performed Per-Esophageal Needle Aspiration of Parenchymal Lung Lesions Using an EBUS Bronchoscope: Diagnostic Utility and Safety

BACKGROUND

Transesophageal introduction of the endobronchial ultrasound (EBUS) videobronchoscope allows pulmonologists to perform endoscopic ultrasound fine-needle aspiration (EUS-B-FNA) of mediastinal lesions. Safety, diagnostic accuracy, and feasibility of EUS-B-FNA in evaluation of pulmonary parenchymal lesions are not established.

METHODS

All patients undergoing pulmonologist-performed EUS-B-FNA of parenchymal lung lesions at 2 tertiary centers were included in this prospective observational cohort study.

RESULTS

EUS-B-FNA sampling of parenchymal lesions was performed in 27 patients. Mean (±SD) lesion size was 36±16 mm. Seven lesions were ≤18 mm. Pneumothorax occurred in 1 patient (3.7%, 95% confidence interval, 0.001%-19%). Ten target lesions (36%) were in locations inaccessible to bronchoscopic sampling via the airways, and 9 lesions were inaccessible to EBUS-guided transbronchial needle aspiration and in locations associated with low diagnostic yield from radial EBUS. EUS-B-FNA was diagnostic in 26 patients (96%), and sensitivity of EUS-B-FNA was 100% (95% confidence interval, 87%-100%) for both lung cancer (n=21) and for pulmonary metastatic lesions (n=5).

CONCLUSIONS

Pulmonologist-performed EUS-B-FNA is safe and accurate in the evaluation parenchymal lung lesions. Diagnostic accuracy is high. EUS-B-FNA may achieve access to sites not amenable to other forms of bronchoscopic sampling, or increase diagnostic accuracy in patients where anatomic position predicts a low diagnostic yield.

When trainees reach competency in performing endoscopic ultrasound: a systematic review

Background/Study aim The American Society for Gastrointestinal Endoscopy (ASGE) recommends that trainees complete 150 endoscopic ultrasound (EUS) procedures before assessing competency. However, this recommendation is largely based on limited evidence and expert opinion. With new evidence suggesting that this historical threshold is underestimating training requirements, we evaluated the learning curve for achieving competency in EUS. Patients/Materials and methods Two investigators independently searched MEDLINE for full-text citations assessing the learning curve for achieving competency in EUS in the period 1946 to 25 March 2016. A learning curve was defined as either a tabulated or graphic representation of competency as a function of increasing EUS experience. Results Eight studies assessing 28 trainees and 7051 EUS procedures were included. When stratifying studies based on procedural indication: three studies assessed competency in evaluating mucosal lesions, three studies assessed competency in EUS fine-needle aspiration (EUS-FNA), and two studies assessed comprehensive competency. Among studies assessing mucosal lesion T-staging accuracy, competency was achieved by 65 to 231 procedures. Among studies assessing EUS-FNA, competency was achieved by 30 to 40 procedures. Among the two studies assessing comprehensive competency in EUS, competency was not achieved in either study across all trainees. Only four of 17 trainees reached competency by 225 to 295 EUS procedures. Conclusion As EUS competency assessment has evolved to more closely reflect independent clinical practice, the number of procedures required to achieve competency has risen well above ASGE recommendations. Advanced endoscopy training programs and specialty societies need to re-assess the structure of EUS training.

Esophageal Endosonography for the Diagnosis of Intrapulmonary Tumors: A Systematic Review and Meta-Analysis

BACKGROUND

Biopsy-based diagnosis in patients with paraesophageal intrapulmonary tumors suspected of lung cancer is crucial for adequate treatment planning.

OBJECTIVE

To evaluate the performance of transesophageal endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in the diagnosis of intrapulmonary tumors located near or adjacent to the esophagus.

METHODS

We performed a systematic review (PROSPERO, CRD42016033737) and searched MEDLINE, Embase, BIOSIS Previews, and Web of Science on September 22, 2016, without date or language restrictions. We included studies that evaluated the yield and/or sensitivity of EUS-FNA for diagnosing intrapulmonary tumors. Yield was defined as the number of patients in whom EUS-FNA made a biopsy-proven diagnosis (malignant or nonmalignant) relative to the total number of patients on whom EUS-FNA was performed. Sensitivity was defined as the number of patients in whom EUS-FNA made a biopsy-proven diagnosis of malignancy relative to the total number of patients in whom the tumor was found to be malignant. We performed a random-effects meta-analysis.

RESULTS

Of 3,320 search results, 11 studies were included. Ten had a high risk of bias. The total number of patients was 313; the proportion of patients with malignancy ranged from 87 to 100% across these studies. The average yield was 0.90 (95% CI 0.82-0.95) and the average sensitivity was 0.92 (0.83-0.96). In the subgroup of prospective studies (n = 3), the average yield was 0.80 (0.56-0.93) and the average sensitivity was 0.83 (0.58-0.95). EUS-FNA-induced complications were reported for 5/256 patients (2.0%) for whom this information was available.

CONCLUSIONS

Although the number of high-quality studies is limited, these findings suggest that EUS-FNA is safe and has a high yield for diagnosing intrapulmonary tumors.

Ultrasound techniques in the evaluation of the mediastinum, part 2: mediastinal lymph node anatomy and diagnostic reach of ultrasound techniques, clinical work up of neoplastic and inflammatory mediastinal lymphadenopathy using ultrasound techniques and how to learn mediastinal endosonography

Ultrasound imaging has gained importance in pulmonary medicine over the last decades including conventional transcutaneous ultrasound (TUS), endoscopic ultrasound (EUS), and endobronchial ultrasound (EBUS). Mediastinal lymph node (MLN) staging affects the management of patients with both operable and inoperable lung cancer (e.g., surgery vs. combined chemoradiation therapy). Tissue sampling is often indicated for accurate nodal staging. Recent international lung cancer staging guidelines clearly state that endosonography should be the initial tissue sampling test over surgical staging. Mediastinal nodes can be sampled from the airways [endobronchial ultrasound combined with transbronchial needle aspiration (EBUS-TBNA)] or the esophagus [endoscopic ultrasound fine needle aspiration (EUS-FNA)]. EBUS and EUS have a complementary diagnostic yield and in combination virtually all MLNs can be biopsied. Additionally endosonography has an excellent yield in assessing granulomas in patients suspected of sarcoidosis. The aim of this review in two integrative parts is to discuss the current role and future perspectives of all ultrasound techniques available for the evaluation of mediastinal lymphadenopathy and mediastinal staging of lung cancer. A specific emphasis will be on learning mediastinal endosonography. Part 1 deals with an introduction into ultrasound techniques, MLN anatomy and diagnostic reach of ultrasound techniques and part 2 with the clinical work up of neoplastic and inflammatory mediastinal lymphadenopathy using ultrasound techniques and how to learn mediastinal endosonography.

How to learn and to perform endoscopic ultrasound and endobronchial ultrasound for lung cancer staging: A structured guide and review

The learning of transesophageal ultrasound guided fine needle aspiration (FNA) (endoscopic ultrasound-FNA), and endobronchial ultrasound guided transbronchial needle aspiration (endosonography) should be based on the following steps: Acquiring theoretical knowledge, training on simulators, and supervised performance on patients. Each step should be completed by passing a validated exam before proceeding to the next step. This approach will assure basic competency on all levels, and testing also facilitates learning and improves retention. Competence in endosonography can be based on a systematic an easy principle consisting of 2 times six anatomical landmarks.

Endobronchial ultrasound learning curve in interventional pulmonary fellows

BACKGROUND AND OBJECTIVE

Little published data exist regarding the learning curve for endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA). We sought to assess the improvement in skill as trainees learned EBUS-TBNA in a clinical setting.

METHODS

This is a multicentre cohort study of EBUS-TBNA technical skill of interventional pulmonology (IP) fellows as assessed with EBUS-TBNA computer simulator testing every 25 clinical cases throughout IP fellowship training.

RESULTS

Nine fellows from three academic centres in the United States and Canada were enrolled in the study. Ongoing improvements were seen for EBUS-TBNA efficiency score and percentage of lymph nodes correctly identified on ultrasound exam, even after 200 clinical cases. Expert-level technical skill was obtained for EBUS efficiency score and for percentage of lymph nodes correctly identified on ultrasound exam at a median of 212 and 164 procedures, respectively; however, 33% of fellows did not achieve expert-level technical skill for either metric during their fellowship training. Significant variation in learning curves of the fellows was observed.

CONCLUSIONS

Significant variation is seen in the EBUS-TBNA learning curves of individual IP fellows and for individual procedure components, with ongoing improvement in EBUS-TBNA skill even after 200 clinical cases. These results highlight the need for validated, objective measures of individual competence, and can assist training programmes in ensuring adequate procedure volumes required for a majority of trainees to successfully complete these assessments.