Using endobronchial ultrasound features to predict lymph node metastasis in patients with lung cancer

PET-CT SUVmax and Endobronchial Ultrasound Features for Prediction of Malignancy: A Prospective Study

INTRODUCTION

Accurate and early staging of lung cancer has a critical impact on its prognosis. EBUS-TBNA is often the procedure of choice for mediastinal staging. Comprehension of the likelihood of malignancy of each lymph node (LN) can assist puncture decision-making during EBUS and offer insight of the procedure expected diagnostic yield.

METHODS

Prospective analysis of mediastinal LN of patients undergoing EBUS-TBNA from April 2021 to May 2022. The relationship between PET-CT SUVmax levels, EBUS features, and malignancy on LN was investigated. For statistical analysis, patients were assigned to 3 groups: suspected malignancy (diagnosis and/or staging), confirmed malignancy (staging) or suspected benign disease.

RESULTS

A total of 363 LN from 132 patients (71% male, mean 62 years old) were analyzed. Among those with suspected benign disease, no LN puncture resulted in a diagnosis of malignancy. PET-CT SUVmax and short axis size were independent factors for malignancy in LN of patients who underwent EBUS for suspected (p < .001 and p = .047, respectively) or confirmed malignancy (p < .001 and p < .001, respectively). All malignant LN presented SUVmax≥1.85 (≥2.85 for staging EBUS cases) and/or short axis size ≥4.28mm. Vascularized LN were more often malignant in either those with suspected (p = .087) or confirmed (p = .095) malignancy, although not statistically significant. LN that were simultaneously vascularized and lacked central hilar structure were also more commonly malignant (p = .013).

CONCLUSION

LN that has higher SUVmax and are larger should be prioritized for puncture, followed by those vascularized and lacking central hilar structure. In staging EBUS cases, a systematic sampling (N3-N2-N1) is required and must precede any malignancy yield rationale.

Performance of endobronchial ultrasound transbronchial needle aspiration as the first nodal staging procedure for the determination of programmed death ligand-1 expression in non-small cell lung cancer patients

PURPOSE

The determination of the programmed death ligand-1 (PD-L1) expression is part of the diagnostic algorithm for advanced non-small cell lung cancer (NSCLC) patients. We aimed to analyze the diagnostic performance of EBUS-TBNA performed as first-choice nodal staging procedure for the determination of PD-L1 expression in NSCLC patients.

METHODS

Longitudinal-prospective study including NSCLC patients diagnosed between January 2018 and October 2019, for whom a primary tumor biopsy sample and an EBUS-TBNA cytological malignant sample were available. Samples with fewer than 100 malignant cells were considered inadequate. PDL-1 IHC 22C3 pharmDx antibody was used. The percentage of tumor cells expressing PD-L1, setting 1% and 50% as cutoff points, was collected. The weighted kappa coefficient was used to assess the concordance of PD-L1 expression. The PD-L1 expression was compared in precision terms.

RESULTS

From a total of 43 patients, 53 pairs of samples were obtained, of which 23 (43.4%) were adequate and included for analysis. The weighted kappa coefficient for PD-L1 expression was 0.41 (95% CI 0.15-0.68) and 0.56 (95% CI 0.23-0.9) for cutoff values ≥ 1% and ≥ 50%, respectively. In advanced stages, the weighted kappa coefficient was 0.6 (95% CI 0.3-0.9) and 1 (95% CI 1-1) for PD-L1 expression cutoff values ≥ 1% and ≥ 50%, respectively. EBUS-TBNA showed a sensitivity, specificity, positive predictive value, and negative predictive value of 1 to detect PDL-1 expression ≥ 50% in advanced stages.

CONCLUSION

EBUS-TBNA performed as first nodal staging procedure in advanced NSCLC patients provides reliable specimens for the detection of PD-L1 expression ≥ 50% and could guide immunotherapy.

Endobronchial ultrasound sonographic characteristics of mediastinal lymph node in evaluation of lung cancer

Endobronchial ultrasound (EBUS) and contrast enhanced computed tomography (CECT) are essential components of lung cancer evaluation. Features of mediastinal lymph nodes on EBUS and CECT can help in predicting metastatic disease. Clinical, radiological and EBUS data of patients with clinico-radiological suspicion of lung cancer and have undergone EBUS with no trans-bronchial needle aspiration (TBNA) or nonyielding EBUS-TBNA were retrospectively collected from medical records. EBUS features of lymph nodes for metastatic disease [Size >1cm, round shape, heterogeneous echo-texture, indistinct margin, coagulation necrosis(CN), absence of central hilar structures (CHS) and grade II-III vascularity] were noted. CECT findings were noted from CECT films and reports to analyse and compare with EBUS findings. Scoring criteria of EBUS sonographic characteristics from previous studies for discriminating benign and malignant lymph-nodes were also assessed for possible prediction. Thirty-one (31) patients [male=18 (58.1%), female=13 (41.9); age (mean±SD) =52.9±15.7 years] with CECT findings suggesting lung cancer were studied. EBUS showed mediastinal lymphadenopathy at 82 lymph node station in 29 patients. Size>1cm, round shape, heterogeneous echo-texture, distinct margin, CN, absence of CHS and grade II-III vascularity at 33 (40%), 28 (34%), 31 (38%), 55 (67%), 3 (4%), 77 (94%) and 6 (7.3%) lymph nodes, respectively. Malignant or benign status assigned to lymph nodes using different scoring criteria were highly discordant. Compared to EBUS, CECT revealed abnormal mediastinal lymph nodes (LN) in significantly less number of patients [21( 67.7%) vs 29 (93.5%), p=0.01] involving less number of lymph node stations (LNS) [(37 vs 82, p<0.001]. Lymphadenopathy frequency at different LNS on EBUS and CECT showed a weak positive but significant correlation (r=0.356; p=0.0426). EBUS characteristics and related scores have limited accuracy in differentiating benign and malignant nodes. CECT underestimates lymph-adenopathy in comparison to EBUS. Larger prospective study of EBUS features with cyto/histo-pathology correlation may elicit its clinical significance and help to create a better and composite scoring criteria.

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

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

Guidelines for endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA): Joint Indian Chest Society (ICS)/Indian Association for Bronchology (IAB) recommendations

Over the past decade, endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has become an indispensable tool in the diagnostic armamentarium of the pulmonologist. As the expertise with EBUS-TBNA has evolved and several innovations have occurred, the indications for its use have expanded. However, several aspects of EBUS-TBNA are still not standardized. Hence, evidence-based guidelines are needed to optimize the diagnostic yield and safety of EBUS-TBNA. For this purpose, a working group of experts from India was constituted. A detailed and systematic search was performed to extract relevant literature pertaining to various aspects of EBUS-TBNA. The modified GRADE system was used for evaluating the level of evidence and assigning the strength of recommendations. The final recommendations were framed with the consensus of the working group after several rounds of online discussions and a two-day in-person meeting. These guidelines provide evidence-based recommendations encompassing indications of EBUS-TBNA, pre-procedure evaluation, sedation and anesthesia, technical and procedural aspects, sample processing, EBUS-TBNA in special situations, and training for EBUS-TBNA.

Correlating Ultrasonographic Features of Lymph Nodes During Endobronchial Ultrasound With Final Outcome

Background

In clinical practice, metastatic primary lung cancer, TB, and sarcoidosis are the commonest causes of mediastinal lymphadenopathy. Differentiation of malignant from benign causes is essential. The sonographic features seem to correlate with malignancy in head and neck, breast, and cervix cancers and can be used to predict the etiology of lesions. The objective of our study was to assess the utility of different ultrasonographic features in differentiating benign and malignant lymph nodes by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA).

Methods

This is a prospective study analysis of all patients above 18 years presenting with mediastinal and hilar adenopathy on computed chest tomography with contrast, undergoing EBUS-TBNA for diagnosis. Lymph node ultrasonographic characteristics such as size, shape, echogenicity, margins, central hilar structure (CHS), and coagulation necrosis sign (CNS) were recorded and compared with histopathology.

Results

A total of 576 patients underwent the EBUS-TBNA procedure, and a total of 810 lymph nodes were evaluated. Three hundred and forty-eight patients (468 lymph nodes) were malignant; 228 patients (342 lymph nodes) were benign. Heterogeneous echotexture was significantly higher in malignant lymph nodes (<0.001). The multivariate analysis revealed that heterogeneous echotexture was an independent predictor for malignant etiology.

Conclusion

Heterogeneous echotexture of the lymph node on EBUS was predictive of malignancy. If heterogenicity is observed on EBUS, subsequent sampling of that lymph node might be considered, which may yield a higher diagnostic yield and may reduce the number of lymph nodes requiring sampling and further invasive procedures.

Clinical Validation of the Canada Lymph Node Score for Endobronchial Ultrasound

BACKGROUND

The Canada Lymph Node Score (CLNS) uses four sonographic criteria to predict the risk of malignancy in lymph nodes during endobronchial ultrasound (EBUS). CLNS may play a role in identifying targets for biopsy or re-biopsy during invasive mediastinal staging for lung cancer. However, CLNS has not yet been prospectively validated in routine clinical practice.

METHODS

CLNS scores for each lymph node biopsied during EBUS were prospectively captured for one year (2019). CLNS and the presence of malignancy in each node were compared. Univariate binary logistic regression was completed for each ultrasonographic feature, as well as a multivariate logistic regression model.

RESULTS

CLNS and diagnostic pathology results were available for 367 lymph nodes. Incidence of malignancy increased with higher scores. Scores ≥3 were significantly associated with malignancy (specificity 84.4%, positive likelihood ratio 4.0). Area under the curve was 0.76, indicating a good ability of the model to predict presence or absence of malignancy. Nodes scoring <2 and negative on CT and PET were malignant in 10.1%.

CONCLUSIONS

CLNS correlates with the presence or absence of malignancy in thoracic lymph nodes, and may serve as an adjunct to currently available methods of invasive and non-invasive mediastinal staging. CLNS may be most helpful to select which non-diagnostic nodes require re-biopsy. There is a significant risk of a false negative result even with a score of 0, and using a combination of low CLNS and negative conventional radiology to obviate the need for any initial biopsy remains to be studied in prospective trials.

The changes on anesthetic practice for non-intubated bronchoscopic interventions during Covid-19 pandemic

Bronchoscopic interventions (BIs) and airway management for bronchoscopy are exceptionally high-risk procedures not only for anesthesiologists, pulmonologists, but also for nursing staff because they expose nurses to COVID-19-containing droplets. However, perioperative changes can be made to the anesthetic management for nonintubated BIs to minimize the spread of COVID-19.

Accuracy and Reproducibility of Endoscopic Ultrasound B-Mode Features for Observer-Based Lymph Nodal Malignancy Prediction

BACKGROUND

Endoscopic ultrasound routinely guides lymph node evaluation for the staging of a known or suspected lung cancer. Characteristics seen on B-mode imaging might help the observer decide on the lymph nodes of risk. The influence of nodal size on the predictivity of these characteristics and the agreement with which operators can combine these for malignancy risk prediction is to be determined.

OBJECTIVES

We evaluated (1) if prospectively scored individual B-mode ultrasound features predict malignancy when further divided by size and (2) assessed if observers were able to reproducibly agree on still lymph node image malignancy risk.

METHODS

Lymph nodes as visualized by EBUS were prospectively scored for B-mode characteristics. Still B-mode images were furthermore collected. After collection, a repeated scoring of a subset of lymph nodes was retrospectively performed (n = 11 observers).

RESULTS

Analysis of 490 lymph nodes revealed the short axis size is an objective measure for stratifying risk of malignancy (ROC area under the curve 0.78). With ≥8-mm size, 210/237 malignant lymph nodes were correctly identified (89% sensitivity, 46% specificity, 61% PPV, and 81% NPV). Secondary addition of B-mode features in <8-mm nodes had limited value. Retrospective analysis of intra- and interobserver scoring furthermore revealed significant disagreement.

CONCLUSIONS

Lymph nodes of ≥8-mm size and preferably even smaller should be aspirated regardless of other B-mode features. Observer disagreement in scoring both small and large lymph nodes suggests it is infeasible to include subjective features for stratification. Future research should focus on (integrating) other (semi)quantitative values for improving prediction.

Mediastinal lymphadenopathy: a practical approach

Introduction: Mediastinal lymphadenopathy is secondary to various benign and malignant etiologies. There is a variation in the underlying cause in different demographic settings. The initial clue to the presence of enlarged mediastinal lymph nodes is through thoracic imaging modalities. Malignancy (Lung cancer, lymphoma, and extrathoracic cancer) and granulomatous conditions (sarcoidosis and tuberculosis) are the most common causes. For a confident diagnosis, the clinician must choose from several available options and integrate the clinical, radiological, and pathology findings. An accurate diagnosis is necessary for optimal management.Areas covered: We performed a search of the PUBMED database to identify relevant articles on the causes, imaging modalities, and interventional modalities to diagnose these conditions. We discuss a practical approach toward the evaluation of a patient with mediastinal lymphadenopathy.Expert opinion: Mediastinal lymphadenopathy is a commonly encountered clinical problem. Treating physicians need to be aware of the clinico-radiological manifestations of the common diagnostic entities. Selecting an appropriate tissue diagnosis modality is crucial, with an intent to use the least invasive technique with good diagnostic yield. Endosonographic modalities (EBUS-TBNA, EUS-FNA, and EUS-B-FNA) have emerged as the cornerstone to most patients' diagnosis. An accurate diagnosis translates into favorable treatment outcomes.

Identification of Specific Endobronchial Ultrasound Features to Differentiate Sarcoidosis From Other Causes of Lymphadenopathy

OBJECTIVES

We hypothesized that specific endobronchial ultrasound (EBUS) features may differentiate sarcoidosis from other causes of lymphadenopathy.

METHODS

We conducted this retrospective observational study from January 2014 to January 2019 to analyze patients with intrathoracic lymphadenopathy who underwent EBUS-guided transbronchial needle aspiration. Ultrasound features, including nodal size, margin, echogenicity, the presence or absence of calcification, a central hilar structure, the coagulation necrosis sign, nodal conglomeration, and the septal vessel sign in the color Doppler mode were recorded and compared between 3 groups.

RESULTS

Of the 90 included patients, 15 had a diagnosis of tuberculosis; 56 had a diagnosis of sarcoidosis; and 19 had a diagnosis of malignant lymph nodes by EBUS-guided transbronchial needle aspiration. The presence of nodal conglomeration (94.6% versus 60.0% versus 5.3%; P < .001), the septal vessel sign in the color Doppler mode (55.4% versus 13.3% versus 15.8%; P = .002), and a distinct margin (73.2% versus 13.3% versus 47.4%; P < .001) were significantly higher in the sarcoidosis group than in the tuberculosis lymphadenopathy and malignant lymph node groups. The presence of the coagulation necrosis sign (8.9% versus 93.3% versus 31.6%; P < .001) was significantly lower in the sarcoidosis group than in tuberculosis lymphadenopathy and malignant lymph node groups. A multivariate analysis showed that the presence of nodal conglomeration, the absence of coagulation necrosis, and the presence of the septal vessel sign in the color Doppler mode were independent predictive factors for the diagnosis of sarcoidosis.

CONCLUSIONS

The presence of nodal conglomeration, the absence of coagulation necrosis, and the presence of the septal vessel sign in the color Doppler mode in lymph nodes on EBUS are predictive of sarcoidosis.

Diagnostic value of endobronchial ultrasound image features: A specialized review

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) technology is important in the diagnosis of intrathoracic benign and malignant lymph nodes (LNs). With the development of EBUS imaging technology, its role in noninvasive diagnosis, as a supplement to pathology diagnosis, has been given increasing attention in recent years. Many studies have explored qualitative and quantitative methods for the three EBUS modes, as well as a variety of multimodal analysis methods, to find the optimal method for the noninvasive diagnosis using EBUS for LNs. Here, we review and comment on the research methods and predictive diagnostic value, discuss the existing problems, and look ahead to the future application of EBUS imaging.

Is Biopsy of Contralateral Hilar N3 Lymph Nodes With Negative PET-CT Scan Findings Necessary When Performing Endobronchial Ultrasound Staging?

BACKGROUND

Systematic endobronchial ultrasound (EBUS)-guided lung cancer staging starts with hilar N3 nodes, proceeding sequentially to mediastinal N3, N2, and N1 nodes, with sampling of all enlarged nodes (size, ≥ 5 mm) by EBUS. However, procedure time is limited by patient comfort when moderate sedation is used. It is unclear if EBUS staging should start with hilar N3 nodes or whether starting with mediastinal N3 nodes suffices. Knowing the probability of hilar N3 nodes with PET-CT scan negative findings harboring occult metastasis can inform this decision.

RESEARCH QUESTION

What proportion of patients with hilar N3 nodes showing negative PET-CT scan findings have malignancy by EBUS?

STUDY DESIGN AND METHODS

This retrospective observational, single-center cohort study included consecutive patients with clinical-radiographic T1-3, N0-3, M0 non-small cell lung cancer undergoing systematic EBUS staging with biopsy of hilar N3 nodes with negative PET-CT scan findings. The primary outcome was the proportion of patients with malignant hilar N3 nodes showing negative PET-CT scan findings. Based on expert opinion, a threshold probability of malignancy of less than 5% was considered sufficient to skip hilar N3 nodes. We used the binomial exact test to compare the observed proportion vs threshold probability of 5%.

RESULTS

Of 1,737 consecutive patients undergoing EBUS staging, 1,567 showed negative PET-CT scan findings of the hilar N3 nodes. These nodes were enlarged by EBUS and were sampled in 739 patients. Malignancy was found in the hilar N3 nodes of 5 of 739 patients (0.68%; 95% CI, 0.22%-1.57%). The proportion was significantly less than the threshold probability (P < .001). Patients with positive PET scan results of the mediastinal N3 nodes were at higher risk of having occult hilar N3 nodal metastasis (P = .003), found in 3 of 46 patients (6.5%; 95% CI, 1.4%-17.9%) with positive PET scan results of the mediastinal N3 nodes.

INTERPRETATION

When using moderate sedation, because time is limited, it is reasonable to start with the mediastinal N3 nodes if the hilar and mediastinal N3 nodes show negative PET scan results. Patients with positive PET scan findings of the mediastinal N3 nodes probably should undergo hilar N3 node sampling.

Diagnosis and invasive staging: Non-surgical invasive mediastinal staging. Endobronchial ultrasound

The diagnosis and staging of lung cancer are an important process that identifies treatment options and guides disease prognosis. Therefore, an accurate mediastinal lymph node (LN) staging is required not only to offer the appropriate treatment but also to avoid unnecessary invasive procedures. At present, endobronchial ultrasound (EBUS)-transbronchial needle aspiration is the preferred modality for sampling mediastinal lymph nodes because of its minimally invasive nature and high diagnostic yield. In this review, we discuss the utility of EBUS in mediastinal LN staging of non-small cell lung cancer (NSCLC).

RELEVANCE FOR PATIENTS

The use of EBUS-TBNA in the diagnosis of mediastinal and hilar LN pathology has become in an essential endoscopic technique and the first step for staging of lung cancer.

Diagnostic utility of endobronchial ultrasound (EBUS) features in differentiating malignant and benign lymph nodes - A systematic review and meta-analysis

BACKGROUND

EBUS is being widely used today for echolocation of lymph nodes for FNAC. We present a systematic review and meta-analysis to assess the diagnostic accuracy of EBUS characteristics of lymph nodes in diagnosing malignancy.

METHODS

A systematic search of published literature was undertaken using databases like PubMed, Web of Science, Cochrane, Google Scholar and Researchgate. Those studies reporting any endobronchial ultrasonography features of malignant lymph nodes like size, margins, echogenicity, shape, central hilar structure (CHS), coagulation necrosis sign (CNS) or color power doppler index (CPDI) were included for review. Random effects model was used to calculate pooled sensitivity, specificity, positive and negative likelihood ratios (LR), and diagnostic odds ratio (DOR). The review protocol was registered with the International prospective register of systematic reviews (PROSPERO registration no. CRD42019117716).

RESULTS

992 articles were retrieved of which 542 articles were evaluated in detail and finally 29 articles met the inclusion criteria. All EBUS features except CPDI showed a statistically significant area under the SROC curve. CNS showed highest area under the SROC curve [0.81 (SE: 0.09)] with maximum pooled specificity [0.93, 95%CI: 0.92-0.94], maximum pooled LR+ [5.12, 95%CI: 2.56-10.2] and DOR [9.23, 95%CI 3.85-22.15]. Maximum sensitivity was seen for CHS 0.91 [95%CI: 0.90-0.92].

CONCLUSION

EBUS features have the potential to help in more precise location of a malignant lymph node thereby helping in increasing the diagnostic yield. However, high diagnostic accuracy of various EBUS features can currently only be said to supplement tissue diagnosis.

Identification of Sonographic Features for Predicting Benign Versus Malignant Mediastinal or Hilar Lymph Nodes Using Endobronchial Ultrasound

Objectives

In countries with a high prevalence of tuberculosis, such as Iran, the differentiation of malignant from non-malignant tumors is crucial. We attempted to find a reliable model in determining malignant nodes by investigating the sonographic characteristics of lymph nodes (LNs).

Methods

In this prospective study, the morphologic characteristics of LNs, including size, shape, vascular pattern, echogenicity, margin, coagulation necrosis sign, calcification, and central hilar structure, which had been obtained during endobronchial ultrasound-guided transbronchial needle aspiration, were compared with the final pathology results.

Results

We examined 253 LNs from 93 patients. Round shape, non-hilar vascular pattern, heterogeneous echogenicity, hyperechogenicity, distinct margin, and the existence of necrosis signs were significantly higher in malignant nodes. On the other hand, the existence of calcification, as well as the presence of central hilar structure, were highly suggestive of benign nodes (p < 0.050). Multivariate logistic regression revealed that size > 1 cm, heterogeneous echogenicity, hyperechogenicity, the existence of necrosis signs, and the lack of central hilar structure are independent predictive factors for malignancy. The accuracy of each of the aforementioned characteristics are 42.3%, 71.5%, 71.9%, 73.5%, and 65.6%, respectively. Of 74 malignant LNs, 100% had at least one of these independent factors.

Conclusions

The morphological features of LNs based on endobronchial ultrasound-guided transbronchial needle aspiration can play a role in predicting malignancy.

The diagnostic accuracy of endobronchial ultrasound and spiral chest computed tomography scan in the prediction of infiltrating and non-infiltrating lymph nodes in patients undergoing endobronchial ultrasound

Purpose

Endobronchial ultrasound (EBUS) and spiral chest computed tomography (CT) scan are important methods in the prediction of infiltrating and non-infiltrating lymph nodes, and the determination of their diagnostic accuracy would result in a reduction of the burden of problems and an improvement in prognosis. The purpose in this study was to determine the diagnostic accuracy of endobronchial ultrasound and spiral chest CT scan in the prediction of infiltrating and non-infiltrating lymph nodes in patients undergoing endobronchial ultrasound.

Material and methods

In this observational prospective study, 40 consecutive patients with infiltrating and non-infiltrating lymph nodes in Masih-Daneshvari Hospital in 2017 and 2018 were enrolled, and the sensitivity, specificity, and accuracy of EBUS and CT-scan versus fine needle aspiration pathology results were determined in them.

Results

The results in this study demonstrated that the congruence between EBUS and CT scan was 80.5% (p = 0.0001). The sensitivity, specificity, and accuracy for CT scan were 100%, 22.6%, and 40%, respectively, and the sensitivity, specificity, and accuracy for EBUS were 100%, 16.1%, and 35%, respectively.

Conclusion

According to the obtained results, it may be concluded that CT scan and EBUS results have good congruence and high sensitivity to differentiate infiltrating and non-infiltrating lymph nodes. Hence, these methods are useful for screening methods, but due to their low specificity and accuracy the use of them for a confirmative approach is not beneficial. However, regarding the accessibility and less invasive nature, use of chest CT scan is more rational and is recommended in these patients.

Mediastinal lymph node staging for lung cancer

Mediastinal lymph node staging is crucial in deciding the treatment strategy for lung carcinoma. The diagnosis rate of computed tomography is not high; however, it is a standard examination. Although the contrast computed tomography is necessary for an accurate diagnosis, images from the positron emission tomography are excellent, and these two technologies are independent and complementary. Positron emission tomography has a disadvantage of false positives and false negatives, but it should also be used in cases where lymph node diameters are 1 cm or more. However, image-based diagnostic methods are not an alternative to histological examination. The results of a transbronchial needle biopsy are extremely dependent on the inspection method, the diagnostic ability of the physician, and the staging of the case. The transesophageal ultrasound endoscope is useful for reaching parts inaccessible by a mediastinoscope. Although its employment requires technical training, it is becoming popular as a minimally invasive method of obtaining cell and the tissue samples. A thoracoscopic biopsy is considered as a last resort for mediastinal lymph node diagnosis. Carefully-chosen invasive procedures are necessary to diagnose swollen lymph nodes. Although mediastinoscopy is still considered as the gold standard, most procedures will be replaced by a comparatively minimally invasive method in the future.

Comparison of specimen adequacy and diagnostic accuracy of a 25-gauge and 22-gauge needle in endobronchial ultrasound-guided transbronchial needle aspiration

Background

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is the preferred diagnostic modality for sampling mediastinal and hilar lymph nodes (LNs). The conventional needle used for sampling is either a 21-gauge (21G) or 22-gauge (22G). A 25-gauge (25G) needle has recently been introduced with little known regarding its efficacy.

Methods

A retrospective study was conducted on patients referred for EBUS-TBNA who had LNs sampled using a 25G or 22G needle. A propensity score matching analysis was performed. After matching the groups, each LN was assessed for adequacy and final diagnosis. Non-diagnostic and benign lymphoid specimens were compared with repeat biopsy findings or long-term clinical and radiological follow-up.

Results

A total of 158 LNs were included. An adequate sample was obtained in 92.4% (73/79) in the 25G group and 92.4% (73/79) in the 22G group (P=1). The 25G group diagnosed benign lymphoid tissue in 82.3% (65/79), granuloma in 7.6% (6/79) and malignancy in 2.5% (2/79). Six lymph nodes in the 25G group were non-diagnostic (7.6%). The 22G group diagnosed benign lymphoid tissue in 83.5% (66/79), granuloma in 3.8% (3/79) and malignancy in 5.1% (4/79). Six lymph nodes in the 22G group were non-diagnostic (7.6%). The sensitivity, specificity, negative predictive value (NPV) and diagnostic accuracy in the 25G group was 88.9% (95% CI, 51.8-99.7%), 100% (95% CI, 92.1-100%), 97.8% (95% CI, 87.6-99.7%) and 98.2% (95% CI, 90.1-100%), respectively. The sensitivity, specificity, NPV and diagnostic accuracy in the 22G group was 77.8% (95% CI, 40-97.2%), 100% (95% CI, 86.8-100%), 92.9% (95% CI, 79.3-97.8%) and 94.3% (95% CI, 80.8-99.3%), respectively. The 25G and 22G group were comparable in diagnostic accuracy (P=0.7).

Conclusions

The 25G and 22G needle achieve comparable specimen adequacy and diagnostic accuracy in EBUS-TBNA.

Optimal Endobronchial Ultrasound Strain Elastography Assessment Strategy: An Explorative Study

BACKGROUND

In lung cancer staging, mediastinal lymph nodes are currently aspirated using endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) based on size and FDG-PET avidity. EBUS strain elastography (SE) is a new technique that may help predict the presence of malignancy. However, a standardized assessment strategy for EBUS-SE measurement is lacking.

OBJECTIVES

The aim of this study was to determine the optimal assessment strategy for investigating the predictive value of EBUS-SE in mediastinal lymph nodes.

METHODS

Two qualitative visual analogue scale strain scores and two semiquantitative strain elastography measurements (a strain histogram and strain ratio) were acquired in 120 lymph nodes of 63 patients with (suspected) lung cancer. The dataset was randomized into an 80% training dataset to determine cut-off values. Performance was consecutively tested on the remaining 20% and the overall dataset.

RESULTS

The semiquantitative mean histogram scoring strategy with a cut-off value of 78 (range 0-255) showed the best and most reproducible performance in prediction of malignancy with 93% overall sensitivity, 75% specificity, 69% positive predictive value, 95% negative predictive value, and 82% accuracy. Combining the EBUS-SE mean histogram scoring outcome with PET-CT information increased the post-test probability of disease in relevant clinical scenarios, having a positive test likelihood ratio of 4.16 (95% CI 2.98-8.13) and a negative test likelihood ratio of 0.14 (95% CI 0.04-2.81) in suspicious lymph nodes based on FDG-PET or CT imaging.

CONCLUSIONS

EBUS-SE can potentially help predict lymph node malignancy in patients with lung cancer. The best semiquantitative assessment method is the mean strain histogram technique.

Needle-based Optical Coherence Tomography to Guide Transbronchial Lymph Node Biopsy

BACKGROUND

Transbronchial needle aspiration (TBNA), often used to sample lymph nodes for lung cancer staging, is subject to sampling error even when performed with endobronchial ultrasound. Optical coherence tomography (OCT) is a high-resolution imaging modality that rapidly generates helical cross-sectional images. We aim to determine if needle-based OCT can provide microstructural information in lymph nodes that may be used to guide TBNA, and improve sampling error.

METHODS

We performed ex vivo needle-based OCT on thoracic lymph nodes from patients with and without known lung cancer. OCT imaging features were compared against matched histology.

RESULTS

OCT imaging was performed in 26 thoracic lymph nodes, including 6 lymph nodes containing metastatic carcinoma. OCT visualized lymphoid follicles, adipose tissue, pigment-laden histiocytes, and blood vessels. OCT features of metastatic carcinoma were distinct from benign lymph nodes, with microarchitectural features that reflected the morphology of the carcinoma subtype. OCT was also able to distinguish lymph node from adjacent airway wall.

CONCLUSIONS

Our results demonstrate that OCT provides critical microstructural information that may be useful to guide TBNA lymph node sampling, as a complement to endobronchial ultrasound. In vivo studies are needed to further evaluate the clinical utility of OCT in thoracic lymph node assessment.

The Contribution of Ultrasonographic Characteristics of Mediastinal Lymph Nodes on Differential Diagnosis of Tuberculous Lymphadenitis from Sarcoidosis

BACKGROUND

Sarcoidosis and Mediastinal Tuberculous Lymphadenitis (MTLA) are two granulomatous diseases. Differentiation between these two diseases is dependent on clinical presentation, microbiological investigation, and cytopathological examination. In endemic regions, differential diagnosis of MTLA and sarcoidosis might be difficult. Endobronchial ultrasound guided Transbronchial Needle Aspiration (EBUS-TBNA) is a new diagnostic procedure for the diagnosis of mediastinal lymphadenopathy. EBUS not only enables the sampling of Lymph Nodes (LN), but also visualization of sonographic features of them. We hypothesized that the sonographic features of LN may help to differentiate MTLA from sarcoidosis.

MATERIALS AND METHODS

This is a retrospective analysis of patients with intrathoracic lymphadenopathy who underwent EBUS-TBNA and were finally diagnosed as sarcoidosis or MTLA. Size, shape, margin, echogenicity, and coagulation necrosis were compared between the groups.

RESULTS

A total of 257 LNs (215 sarcoidosis, 42 MTLA) were examined in 101 patients. A heterogeneous echotexture of lymph nodes was significantly more common (P <0.0001) in MTLA (69%) than sarcoidosis (36.2%). Also, necrosis was statistically significantly higher in MTLA compared to sarcoidosis (P<0.0001). The vascular pattern was similar in both groups (P=0.9050). Nearly half of the patients had grade 1 vascular pattern in both groups. The odds for diagnosis of MTLA were significantly higher in the presence of heterogeneous echotexture (odds ratio [OR], 7,00) or necrosis sign (OR, 131,2).

CONCLUSION

Vascular patterns of two diseases were similar. Heterogeneous echotexture and necrosis sign in the LNs on EBUS are specific for MTLA. Combination of these findings with a positive tuberculin skin test, favors the diagnosis of MTLA over sarcoidosis.

Diagnostic Imaging and Newer Modalities for Thoracic Diseases: PET/Computed Tomographic Imaging and Endobronchial Ultrasound for Staging and Its Implication for Lung Cancer

Modalities to detect and characterize lung cancer are generally divided into those that are invasive [endobronchial ultrasound (EBUS), esophageal ultrasound (EUS), and electromagnetic navigational bronchoscopy (ENMB)] versus noninvasive [chest radiography (CXR), computed tomography (CT), positron emission tomography (PET), and magnetic resonance imaging (MRI)]. This chapter describes these modalities, the literature supporting their use, and delineates what tests to use to best evaluate the patient with lung cancer.

Diagnostic Imaging and Newer Modalities for Thoracic Diseases: PET/Computed Tomographic Imaging and Endobronchial Ultrasound for Staging and Its Implication for Lung Cancer

Modalities to detect and characterize lung cancer are generally divided into those that are invasive [endobronchial ultrasound (EBUS), esophageal ultrasound (EUS), and electromagnetic navigational bronchoscopy (ENMB)] versus noninvasive [chest radiography (CXR), computed tomography (CT), positron emission tomography (PET), and magnetic resonance imaging (MRI)]. This chapter describes these modalities, the literature supporting their use, and delineates what tests to use to best evaluate the patient with lung cancer.

Understanding local performance data for EBUS-TBNA: insights from an unselected case series at a high volume UK center

BACKGROUND

We reviewed the diagnostic performance of endobronchial ultrasound transbronchial aspiration (EBUS-TBNA) on an unselected large cohort of patients who underwent the procedure in our institution in the past 3 years and to compare against published standards and existing literature.

METHODS

All consecutive patients who underwent EBUS from January 2013 to December 2015 were included in the retrospective analysis, with a minimum of 6 months of clinico-radiological follow up. For assessing EBUS-TBNA performance, patients were analysed in three subgroups based on the indication for the EBUS-TBNA: in investigation of isolated mediastinal and/or hilar lymphadenopathy (IMHL), in staging of suspected or confirmed non-small cell lung cancer (NSCLC) and in making a tissue diagnosis in suspected thoracic or extrathoracic cancer. For patients subjected to EBUS-TBNA for staging in suspected lung cancer, accuracy of EBUS was measured by its ability to determine the true N2 stage.

RESULTS

A total of 1,656 lymph nodes and 138 peribronchial/peritracheal masses were sampled in 940 patients over the study period. The prevalence of reactive lymphadenopathy was 34%. The overall sensitivity to detect pathological disease was 81.6% (95% CI: 74.2-87.6%) whilst NPV was 74.8% (95% CI: 65.2-82.8%). Amongst patients who underwent EBUS-TBNA for staging purposes, the sensitivity for N2 staging was 83.7% (95% CI: 76.2-89.6%) and NPV was 81.6% (95% CI: 73.2-88.2%). The prevalence of N2 disease was 58%. In the subgroup of patients who proceeded to surgical sampling, the sensitivity was higher with the N2/N3 disease prevalence of 67.4%. The sensitivity of EBUS-TBNA to make a tissue diagnosis of thoracic or extrathoracic cancer was 88% (95% CI: 85.1-90.5%) and a NPV of 62% (95% CI: 54.7-69.0%). The disease prevalence was 83.6%.

CONCLUSIONS

This retrospective study of a large volume of patients represents real life practice and provides an accurate representation of the typical cohort of patients referred in for EBUS-TBNA to the general respiratory physician in UK. Our study highlights the pitfalls in collecting and analyzing data but also demonstrates how they can be used to improve service performance.

Recent advances in diagnostic bronchoscopy

The field of diagnostic bronchoscopy has been revolutionized in the last decade primarily with the advent of endobronchial ultrasound (EBUS) but also with the addition of multiple different techniques for "guided-bronchoscopy". These advances have had a substantial impact in the management of lung cancer with bronchoscopy now providing both diagnosis and mediastinal staging in a single procedure. EBUS has, in fact, become the first choice for staging of the mediastinum over cervical mediastinoscopy (CM). Although EBUS is now a well-established technique, there are continuous efforts from the scientific community to improve its diagnostic performance, and these will be reviewed in this manuscript. The term "guided-bronchoscopy" was recently coined to describe a myriad of techniques that guide our bronchoscopes or bronchoscopic tools into the periphery of the lungs in addition to our conventional fluoroscopy. Electromagnetic and non-electromagnetic navigation, thin and ultrathin scopes, as well as radial-probe EBUS have collectively increased our yield for smaller peripheral lung lesions and continue to evolve. Despite this improved diagnostic yield, there is still ample room for improvement and newer techniques are under way. With new therapies available for patients with interstitial lung disease, achieving a specific histologic diagnosis is now of paramount importance. Given the high morbidity and mortality of surgical biopsies, bronchoscopic cryobiopsy is being rapidly adopted as a safer and effective alternative, and it is likely going to play a major role in the management of these diseases in the near future. This manuscript we will focus on recent advances in EBUS, guided-bronchoscopy, and the use of cryobiopsy.

Recent advances in endobronchial ultrasound-guided transbronchial needle aspiration

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive modality for sampling of mediastinal and hilar lymph nodes as well as pulmonary lesions adjacent to the airway. Guidelines for staging of lung cancer suggest that EBUS-TBNA should be considered the best first test of nodal staging for radiologically abnormal lymph nodes that are accessible by this approach. The application of EBUS-TBNA in pulmonary medicine and thoracic oncology is expanding with its role in the diagnosis of sarcoidosis, lymphoma, and tuberculosis. Especially for patients with early-stage sarcoidosis with adenopathy and minimal changes in the lung parenchyma, EBUS-TBNA has a significantly higher diagnostic yield compared to the conventional bronchoscopic modalities. Multidirectional analysis of samples obtained by EBUS-TBNA has allowed assessment of lymphoma and molecular analysis in lung cancer. Histological evaluation with immunohistochemistry, flow cytometry, fluorescence in situ hybridization, and chromosome analysis can be performed if good-quality samples can be obtained. Molecular analyses such as identification of epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) fusion gene detection now are being performed routinely with good sampling. One of the advantages of EBUS-TBNA is the ability to perform repeat procedures in a minimally invasive way. Restaging of the mediastinum after induction therapy can be done safely and with ease compared to repeat surgical procedures. With improvement in molecular analysis technology, comprehensive gene expression analysis will become important in the management of patients with lung cancer. Further advances in EBUS technology and needles for tissue sampling likely will help bronchoscopists to acquire ideal tissue.

Diagnostic value of endobronchial ultrasound-guided transbronchial needle aspiration in various lung diseases

Objective:

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a new method for the diagnosis and staging of lung disease, and its use is increasing worldwide. It has been used as a means of diagnosing lung cancer in its initial stages, and there are data supporting its use for the diagnosis of benign lung disease. The aim of this study was to share our experience with EBUS-TBNA and discuss its diagnostic value.

Methods:

We retrospectively analyzed the results related to 159 patients who underwent EBUS-TBNA at our pulmonary medicine clinic between 2010 and 2013. We recorded the location and size of lymph nodes seen during EBUS. Lymph nodes that appeared to be affected on EBUS were sampled at least twice. We recorded the diagnostic results of EBUS-TBNA and (for cases in which EBUS-TBNA yielded an inconclusive diagnosis) the final diagnoses after further investigation and follow-up.

Results:

We evaluated 159 patients, of whom 89 (56%) were male and 70 (44%) were female. The mean age was 54.6 ± 14.2 years among the male patients and 51.9 ± 11.3 years among the female patients. Of the 159 patients evaluated, 115 (84%) were correctly diagnosed by EBUS. The diagnostic accuracy of EBUS-TBNA was 83% for benign granulomatous diseases and 77% for malignant diseases.

Conclusions:

The diagnostic value of EBUS-TBNA is also high for benign pathologies, such as sarcoidosis and tuberculosis. In patients with mediastinal disorders, the use of EBUS-TBNA should be encouraged, primarily because it markedly reduces the need for mediastinoscopy.

PET-Based Percutaneous Needle Biopsy

PET can be used to guide percutaneous needle biopsy to the most metabolic lesion, improving diagnostic yield. PET biopsy guidance can be performed using visual or software coregistration, electromagnetic needle tracking, cone-beam computed tomography (CT), and intraprocedural PET/CT guidance. PET/CT-guided biopsies allow the sampling of lesions that may not be clearly visible on anatomic imaging, or of lesions that are morphologically normal. PET can identify suspicious locations within complex tumors that are most likely to contain important diagnostic and prognostic information.

A new needle on the block: EchoTip ProCore endobronchial ultrasound needle

Endobronchial ultrasound has become the first choice standard of care procedure to diagnose benign or malignant lesions involving mediastinum and lung parenchyma adjacent to the airways owing to its characteristics of being real-time and minimally invasive. Although the incidence of lung cancer has been decreasing, it is and will be the leading cause of cancer-related mortality in the next few decades. When compared to other cancers, lung cancer kills more females than breast and colon cancers combined and more males than colon and prostate cancers combined. The type of lung cancer has changed in recent decades and adenocarcinoma has become the most frequent cell type. Prognosis of lung cancer depends upon the cell type and the staging at the time of diagnosis. The cell type and molecular characteristics of adenocarcinoma may allow individualized targeted treatment. Other malignant conditions in the mediastinum and lung (eg, metastatic lung cancers and lymphoma) can be biopsied using endobronchial ultrasound needles. Endobronchial ultrasound needle biopsies provides mostly cytology specimens due to its small sizes of needles (22 gauge or larger) which may not give enough tissue to make a definitive diagnosis in malignant (eg, lymphoma) or benign conditions (eg, sarcoidosis). EchoTip ProCore endobronchial needle released in early 2014 provides histologic biopsy material. Larger tissue biopsies may potentially provide a higher diagnostic yield and it eliminates mediastinoscopy or other surgical interventions. Here we aim to review bronchoscopic approach in the diagnosis of mediastinal lesions with emphasis of EchoTip ProCore needles.

Mediastinal and Hilar Lymph Node Measurements. Comparison of Multidetector-Row Computed Tomography and Endobronchial Ultrasound

RATIONALE

Multidetector-row chest computed tomography scan is a common initial imaging modality and endobronchial ultrasound is a minimally invasive diagnostic tool used to evaluate enlarged lymph nodes, but comparisons of imaging results are lacking.

OBJECTIVES

To determine the size of thoracic lymph nodes and the strength of agreement between each measurement from coronal plane computed tomography and static endobronchial ultrasound images.

METHODS

A retrospective review of consecutive patients who underwent endobronchial ultrasound-transbronchial needle aspiration of their lymph nodes because of clinical suspicion of benign or malignant thoracic disease.

MEASUREMENTS AND MAIN RESULTS

One hundred and twenty-four lymph nodes from the mediastinal (74.2%) and hilar (25.8%) stations were measured in 59 patients (mean age, 64.5 yr; 33 males). The mean (standard deviation) short-axis diameter on computed tomography was 14.1 (6.7) mm compared with 12.6 (6.6) mm on endobronchial ultrasound. Benign lymph nodes (n = 42) were larger on computed tomography than on endobronchial ultrasound (14.1 [6.2] vs. 11.5 [6.2] mm). Malignant lymph nodes (n = 35) were larger on endobronchial ultrasound than on computed tomography (17.3 [6.4] vs. 16.2 [6.7] mm). Sixty-five percent of the lymph nodes that were initially interpreted as not enlarged on axial computed tomography images measured greater than 10 mm on each imaging modality (12.5 [5.9] mm on computed tomography and 10.5 [5.6] mm on endobronchial ultrasound) and 24% of the sampled lymph nodes from this group contained malignant cells. Random-effects maximal likelihood linear regression showed a statistically significant difference between endobronchial ultrasound and the computed tomography method for measuring short-axis diameter in all 124 lymph nodes. There was a weak agreement (intraclass correlation, rho: 0.44 [95% confidence interval, 0.31-0.59]) between short-axis diameter measurements from each imaging modality.

CONCLUSIONS

Our single-center study shows that there was poor correlation between computed tomography and endobronchial ultrasound for the measurement of mediastinal and hilar lymph nodes. Malignant cells were recovered by ultrasound-guided needle aspiration from a substantial fraction of lymph nodes that were initially interpreted as normal in size. If these findings are confirmed, new criteria may be needed for lymph node measurement on computed tomography that will guide selection of lymph nodes for endobronchial ultrasound-transbronchial needle aspiration.

Technical Aspects of Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration: CHEST Guideline and Expert Panel Report

BACKGROUND

Endobronchial ultrasound (EBUS) was introduced in the last decade, enabling real-time guidance of transbronchial needle aspiration (TBNA) of mediastinal and hilar structures and parabronchial lung masses. The many publications produced about EBUS-TBNA have led to a better understanding of the performance characteristics of this procedure. The goal of this document was to examine the current literature on the technical aspects of EBUS-TBNA as they relate to patient, technology, and proceduralist factors to provide evidence-based and expert guidance to clinicians.

METHODS

Rigorous methodology has been applied to provide a trustworthy evidence-based guideline and expert panel report. A group of approved panelists developed key clinical questions by using the PICO (population, intervention, comparator, and outcome) format that addressed specific topics on the technical aspects of EBUS-TBNA. MEDLINE (via PubMed) and the Cochrane Library were systematically searched for relevant literature, which was supplemented by manual searches. References were screened for inclusion, and well-recognized document evaluation tools were used to assess the quality of included studies, to extract meaningful data, and to grade the level of evidence to support each recommendation or suggestion.

RESULTS

Our systematic review and critical analysis of the literature on 15 PICO questions related to the technical aspects of EBUS-TBNA resulted in 12 statements: 7 evidence-based graded recommendations and 5 ungraded consensus-based statements. Three questions did not have sufficient evidence to generate a statement.

CONCLUSIONS

Evidence on the technical aspects of EBUS-TBNA varies in strength but is satisfactory in certain areas to guide clinicians on the best conditions to perform EBUS-guided tissue sampling. Additional research is needed to enhance our knowledge regarding the optimal performance of this effective procedure.

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.

Endoscopic ultrasound: Elastographic lymph node evaluation

Different imaging techniques can bring different information which will contribute to the final diagnosis and further management of the patients. Even from the time of Hippocrates, palpation has been used in order to detect and characterize a body mass. The so-called virtual palpation has now become a reality due to elastography, which is a recently developed technique. Elastography has already been proving its added value as a complementary imaging method, helpful to better characterize and differentiate between benign and malignant masses. The current applications of elastography in lymph nodes (LNs) assessment by endoscopic ultrasonography will be further discussed in this paper, with a review of the literature and future perspectives.

The sonographic features of malignant mediastinal lymph nodes and a proposal for an algorithmic approach for sampling during endobronchial ultrasound

INTRODUCTION

There are several papers on the sonographic features of mediastinal lymph nodes affected by several diseases, but none gives the importance and clinical utility of the features.

OBJECTIVE

In order to find out which lymph node should be sampled in a particular nodal station during endobronchial ultrasound, we investigated the diagnostic performances of certain sonographic features and proposed an algorithmic approach.

METHODS

We retrospectively analyzed 1051 lymph nodes and randomly assigned them into a preliminary experimental and a secondary study group. The diagnostic performances of the sonographic features (gray scale, echogeneity, shape, size, margin, presence of necrosis, presence of calcification and absence of central hilar structure) were calculated, and an algorithm for lymph node sampling was obtained with decision tree analysis in the experimental group. Later, a modified algorithm was applied to the patients in the study group to give the accuracy.

RESULTS

The demographic characteristics of the patients were not statistically significant between the primary and the secondary groups. All of the features were discriminative between malignant and benign diseases. The modified algorithm sensitivity, specificity, and positive and negative predictive values and diagnostic accuracy for detecting metastatic lymph nodes were 100%, 51.2%, 50.6%, 100% and 67.5%, respectively.

CONCLUSIONS

In this retrospective analysis, the standardized sonographic classification system and the proposed algorithm performed well in choosing the node that should be sampled in a particular station during endobronchial ultrasound.

Utility of GATA3, mammaglobin, GCDFP-15, and ER in the detection of intrathoracic metastatic breast carcinoma

INTRODUCTION

Breast carcinoma (BC) metastatic to the intrathoracic cavity is difficult to diagnose due to low sensitivity of current immunohistochemical (IHC) stains. Mammaglobin, gross cystic disease fluid protein-15 (GCDFP-15), and estrogen receptor (ER) immunomarkers show variable results. GATA3 is a recently described marker for detecting urothelial and breast cancers. Our goal is to test the utility of GATA3 in cell blocks from thoracic cytology specimens.

MATERIALS AND METHODS

We retrieved cases of BC that metastasized to the thoracic cavity from January 1, 2005 to September 30, 2013. IHC was performed on the cell blocks for the presence of GATA3, ER, GCDFP-15, and mammaglobin. Stains were scored quantitatively and qualitatively.

RESULTS

Fifty cases of metastatic BC found in pleural effusions and endobronchial ultrasound-guided fine-needle aspirates were identified in 48 patients. Thirty-four cases had sufficient material for IHC (19 pleural effusions, 15 endobronchial ultrasound-guided fine-needle aspirates). GATA3 showed strong nuclear positivity in 31 of 34 cases (91.2%). ER (25 of 34, 73.5%), mammaglobin (23 of 34, 67.6%) and GCDFP-15 (11 of 34, 32.6%) were positive in fewer cases. GATA3 and ER were concordant in 26 of 34 cases (76.5%) (24 ER/GATA3-positive, 2 ER/GATA3-negative). Discordant results were found in 8 of 34 cases (23.5%). Of these, GATA3 was positive and ER was negative in 7 cases. GATA3 was negative and ER was positive in 1 case.

CONCLUSIONS

GATA3 is more sensitive than ER, mammaglobin, or GCDFP-15 in detecting metastatic BC in cytologic specimens. GATA3 may be positive when ER is negative. In cytologic specimens with limited diagnostic material, GATA3 may be used as a first-line marker in a limited IHC panel to support metastatic BC.

Histogram-based quantitative evaluation of endobronchial ultrasonography images of peripheral pulmonary lesion

BACKGROUND

Endobronchial ultrasonography using a guide sheath (EBUS-GS) is an increasingly common bronchoscopic technique, but currently, no methods have been established to quantitatively evaluate EBUS images of peripheral pulmonary lesions.

OBJECTIVES

The purpose of this study was to evaluate whether histogram data collected from EBUS-GS images can contribute to the diagnosis of lung cancer.

METHODS

Histogram-based analyses focusing on the brightness of EBUS images were retrospectively conducted: 60 patients (38 lung cancer; 22 inflammatory diseases), with clear EBUS images were included. For each patient, a 400-pixel region of interest was selected, typically located at a 3- to 5-mm radius from the probe, from recorded EBUS images during bronchoscopy. Histogram height, width, height/width ratio, standard deviation, kurtosis and skewness were investigated as diagnostic indicators.

RESULTS

Median histogram height, width, height/width ratio and standard deviation were significantly different between lung cancer and benign lesions (all p < 0.01). With a cutoff value for standard deviation of 10.5, lung cancer could be diagnosed with an accuracy of 81.7%. Other characteristics investigated were inferior when compared to histogram standard deviation.

CONCLUSIONS

Histogram standard deviation appears to be the most useful characteristic for diagnosing lung cancer using EBUS images.

Nodal staging in lung cancer: a risk stratification model for lymph nodes classified as negative by EBUS-TBNA

BACKGROUND

Over the last 10 years, endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has become established as the first-line nodal staging procedure of choice for lung cancer patients. However, the pathway for patients following a negative EBUS-TBNA has not been clearly defined. The primary aim of this study was to develop and validate a risk stratification model to categorize lymph nodes deemed negative by EBUS-TBNA into "low-risk" and "high-risk" groups, where "risk" refers to the risk of false negative sampling.

METHODS

A retrospective analysis of a prospectively maintained database at a UK tertiary EBUS-TBNA centre was performed. Only patients with primary lung cancer and only negative lymph nodes by EBUS-TBNA were included in the analysis. A risk stratification model was built from a derivation set using independent predictors of malignancy and the validation set used to evaluate the constructed model. The study period was from March 2010 to August 2013.

RESULTS

Three hundred twenty-nine lymph nodes were included in the analysis (derivation set n = 196, validation set n = 133). Lymph node standardized uptake value, the standardized uptake value ratio between the lymph node and primary tumor, and heterogeneous echogenicity during sonographic assessment were the only independent predictors of malignancy. Using a simplified scoring system based on the natural logs of the odds ratios from the multivariable analysis on the derivation sample, lymph nodes can be stratified into low risk (score ≤1) and high risk (score ≥2). One hundred forty-one of 142 and 94 of 96 lymph nodes classified as low risk in the derivation and validation set, respectively, were ultimately proven to be benign and 35 of 54 and 24 of 37 lymph nodes classified as high risk were proven malignant. The negative predictive value of the risk stratification model for the derivation set and validation set was 99.3% (95% confidence interval 96.1%-99.6%) and 97.9% (95% confidence interval 92%-99.6%), respectively.

CONCLUSION

This risk stratification model may assist lung cancer multidisciplinary teams in deciding which patients need further staging procedures and which may proceed directly to treatment after a negative EBUS.

Clinical value of endobronchial ultrasound findings for predicting nodal metastasis in patients with suspected lymphadenopathy: a prospective study

We evaluated whether sonographic findings can provide additional diagnostic yield in endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), and can more accurately predict nodal metastasis than chest computed tomography (CT) or positron emission tomography (PET)/CT scans. EBUS-TBNA was performed in 146 prospectively recruited patients with suspected thoracic lymph node involvement on chest CT and PET/CT from June 2012 to January 2013. Diagnostic yields of EBUS finding categories as a prediction model for metastasis were evaluated and compared with findings of chest CT, PET/CT, and EBUS-TBNA. In total, 172 lymph nodes were included in the analysis: of them, 120 were malignant and 52 were benign. The following four EBUS findings were predictive of metastasis: nodal size ≥10 mm, round shape, heterogeneous echogenicity, and absence of central hilar structure. A single EBUS finding did not have sufficient diagnostic yield; however, when the lymph node had any one of the predictive factors on EBUS, the diagnostic yields for metastasis were higher than for chest CT and PET/CT, with a sensitivity of 99.1% and negative predictive value of 83.3%. When any one of predictive factors is observed on EBUS, subsequent TBNA should be considered, which may provide a higher diagnostic yield than chest CT or PET/CT.

Staging lung cancer: role of endobronchial ultrasound

Accurate staging is the first step in the management of lung cancer. Nodal staging is quite important for physicians to be able to judge the primary operability of patients harboring no distant metastasis. For many years, mediastinoscopy has been considered a "gold standard" modality for nodal staging. Mediastinoscopy is known to be a highly sensitive procedure for mediastinal staging and has been performed worldwide, but is invasive. Because of this, clinicians have sought a less invasive modality for nodal staging. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive modality for diagnosis and staging of lung cancer. EBUS-TBNA is a needle biopsy procedure that has accessibility compatible with the reach of the convex-probe EBUS scope, so N1 nodes are also assessable. The diagnostic yield is similar to that of mediastinoscopy, and the core obtained by the dedicated needle biopsy can be used for histological assessment to determine the subtypes of lung cancer. The samples can also be used to test for various biomarkers using immunohistochemistry, polymerase chain reaction for DNA/complementary DNA, and in situ hybridization, and the technique is useful for selecting candidates for specific molecular-targeted therapeutic agents. According to the newly published American College of Chest Physicians guideline, EBUS-TBNA is now considered "the best first test" for nodal staging in patients with radiologically suspicious nodes. Appropriate training and thorough clinical experience is required to be able to perform correct nodal staging using this procedure.

Endobronchial ultrasound-guided transbronchial needle aspiration for non-small cell lung cancer staging

Real-time endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is an established technique for invasive mediastinal staging of non-small cell lung cancer (NSCLC). Needle-based techniques are now recommended as a first-line diagnostic modality for mediastinal staging. Accurate performance of systematic staging with EBUS-TBNA requires a detailed knowledge of mediastinal anatomy. This examination begins at the N3 lymph nodes, progressing through the N2 and N1 lymph node stations, unless a higher station lymph node is positive for malignant cells by rapid on-site cytologic examination. Objective methods of identifying EBUS-TBNA targets include sampling any lymph node station with a visible lymph node or with a lymph node greater than 5 mm in short axis. Three passes per station or the use of rapid on-site cytologic examination with identification of diagnostic material (tumor or lymphocytes) up to five passes are well-established techniques. Obtaining sufficient tissue for molecular profiling may require performing more than three passes. The operating characteristics of EBUS-TBNA are similar to mediastinoscopy. However, mediastinoscopy should be considered in the setting of a negative EBUS-TBNA and a high posterior probability of N2 or N3 involvement.

Real-time prediction of mediastinal lymph node malignancy by endobronchial ultrasound

OBJECTIVE

To evaluate the utility of different ultrasonographic (US) features in differentiating benign and malignant lymph node (LN) by endobronchial ultrasound (EBUS) and validate a score for real-time clinical application.

METHODS

208 mediastinal LN acquired from 141 patients were analyzed. Six different US criteria were evaluated (short axis ≥10 mm, shape, margin, echogenicity, and central hilar structure [CHS], and presence of hyperechoic density) by two observers independently. A simplified score was generated where the presence of margin distinction, round shape and short axis ≥10 mm were scored as 1 and heterogeneous echogenicity and absence of CHS were scored as 1.5. The score was evaluated prospectively for real-time clinical application in 65 LN during EBUS procedure in 39 patients undertaken by two experienced operators. These criteria were correlated with the histopathological results and the sensitivity, specificity, positive and negative predictive values (PPV and NPV) were calculated.

RESULTS

Both heterogenicity and absence of CHS had the highest sensitivity and NPV (≥90%) for predicting LN malignancy with acceptable inter-observer agreement (92% and 87% respectively). On real-time application, the sensitivity and specificity of the score >5 were 78% and 86% respectively; only the absence of CHS, round shape and size of LN were significantly associated with malignant LN.

CONCLUSIONS

Combination of different US criteria can be useful for prediction of mediastinal LN malignancy and valid for real-time clinical application.

Differentiating tuberculosis from sarcoidosis by sonographic characteristics of lymph nodes on endobronchial ultrasonography: a study of 165 patients

OBJECTIVE

The differential diagnosis of sarcoidosis and tuberculosis is difficult, especially in countries with a high tuberculosis burden. We hypothesized that sonographic features on endobronchial ultrasonography (EBUS) would help in differentiating tuberculosis from sarcoidosis. In this study, the endosonographic features of tuberculosis and sarcoidosis are compared.

METHODS

This was a retrospective analysis of prospectively collected data of patients with intrathoracic lymphadenopathy who underwent EBUS-guided transbronchial needle aspiration (TBNA), and were finally diagnosed with sarcoidosis or tuberculosis. Sonographic features such as size, shape (round or oval), margin (distinct or indistinct), echogenicity (heterogeneous or homogeneous), presence or absence of a central hilar structure, and coagulation necrosis sign were recorded and compared in the 2 groups.

RESULTS

During the study period, 249 EBUS-guided TBNA procedures were performed and a diagnosis of sarcoidosis (n = 118) or tuberculosis (n = 47) was made in 165 patients. A total of 358 lymph node stations were examined. Heterogeneous echotexture (53.4% vs 12.6%, P < .001) and coagulation necrosis (26.1% vs 3.3%; P < .001) were significantly higher in tuberculous lymph nodes. A combination of a positive tuberculin skin test (TST) and either heterogeneous echotexture or coagulation necrosis sign had specificity of 98% and positive predictive value of 91% for a diagnosis of tuberculosis.

CONCLUSIONS

Sonographic features of heterogeneous echotexture or coagulation necrosis in the lymph nodes on EBUS are fairly specific for tuberculosis. Along with a positive TST, these features strongly favor a diagnosis of tuberculosis over sarcoidosis.

An update on the evaluation and management of small pulmonary nodules

The widespread utilization of chest CT scans has increased the importance of the proper evaluation of incidentally found lung nodules. The primary goal in the evaluation of these nodules is to determine whether they are malignant or benign. Clinical factors such as older age, tobacco smoking, and current or remote history of malignancy increase the pretest likelihood of malignancy. Radiological features of these nodules are important in differentiating benign from malignant lesions. However, the etiology of the lung nodules frequently remains indeterminate and requires further evaluation. The approach to the management of indeterminate lung nodules ranges between observation with repeat chest CT scan, further diagnostic studies such as PET scan or invasive procedures to obtain tissue diagnosis. This article reviews the importance of the different radiological features of lung nodules. This is followed by an update on the approach to the management of the different types of small lung nodules.

Technical aspects of endobronchial ultrasound-guided transbronchial needle aspiration

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is becoming a standard method for invasive mediastinal staging and for the diagnosis of paratracheal and peribronchial lesions. It is essential to understand the technical aspects of EBUS-TBNA to ensure safe and efficient procedures. In this review, we discuss the practical aspects to be considered during EBUS-TBNA, including anesthesia, manipulation of equipment, understanding mediastinal ultrasound images, target selection, number of aspirations needed per target, sample handling, and complications.

Linear EBUS in staging non-small cell lung cancer and diagnosing benign diseases

As an evolving technique, linear endobronchial ultrasound is becoming the first choice and standard of care not only to diagnose the malignant and benign mediastinal lesions but also to stage non-small cell lung cancer. Lung cancer is the leading cause of cancer-related mortality in both men and women. The disease causes more death compared with colorectal, breast, and prostate cancers combined in the United States. Staging of lung cancer determines the prognosis. The type of lung cancer has changed in the past few decades. The frequency of adenocarcinoma has increased, whereas squamous cell carcinoma now is less frequent. Determining the cell type and its molecular characteristics allow targeted treatments in adenocarcinoma. The diagnosis of indeterminate mediastinal lymph nodes or masses and staging lung cancer might be challenging. This article will review the principles and clinical utility of endobronchial ultrasound in mediastinal lesions.