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

Intrathoracic Lymph Node Microcalcifications are Associated With a High Prevalence of Malignancy and Anaplastic Lymphoma Kinase Rearrangement: The "Calce" Study

BACKGROUND

Microcalcifications are acknowledged as a malignancy risk factor in multiple cancers. However, the prevalence and association of intrathoracic lymph node (ILN) calcifications with malignancy remain unexplored.

METHODS

In this cross-sectional study, we enrolled patients with known/suspected malignancy and an indication for endosonography for diagnosis or ILN staging. We assessed the prevalence and pattern of calcified ILNs and the prevalence of malignancy in ILNs with and without calcifications. In addition, we evaluated the genomic profile and PD-L1 expression in lung cancer patients, stratifying them based on the presence or absence of ILN calcifications.

RESULTS

A total of 571 ILNs were sampled in 352 patients. Calcifications were detected in 85 (24.1%) patients and in 94 (16.5%) ILNs, with microcalcifications (78/94, 83%) being the predominant type. Compared with ILNs without calcifications (214/477, 44.9%), the prevalence of malignancy was higher in ILNs with microcalcifications (73/78, 93.6%; P<0.0001) but not in those with macrocalcifications (7/16, 43.7%; P=0.93). In patients with lung cancer, the high prevalence of metastatic involvement in ILNs displaying microcalcifications was independent of lymph node size (< or >1 cm) and the clinical stage (advanced disease; cN2/N3 disease; cN0/N1 disease). The anaplastic lymphoma kinase (ALK) rearrangement was significantly more prevalent in patients with than in those without calcified ILNs (17.4% vs. 1.7%, P<0.001), and all of them exhibited microcalcifications.

CONCLUSION

ILN microcalcifications are common in patients undergoing endosonography for suspected malignancy, and they are associated with a high prevalence of metastatic involvement and ALK rearrangement.

A risk-scoring model based on endobronchial ultrasound multimodal imaging for predicting metastatic lymph nodes in lung cancer patients

Background and Objectives

Endobronchial ultrasound (EBUS) imaging is a valuable tool for predicting lymph node (LN) metastasis in lung cancer patients. This study aimed to develop a risk-scoring model based on EBUS multimodal imaging (grayscale, Doppler mode, elastography) to predict LN metastasis in lung cancer patients.

Patients and Methods

This retrospective study analyzed 350 metastatic LNs in 314 patients with lung cancer and 124 reactive LNs in 96 patients with nonspecific inflammation. The sonographic findings were compared with the final pathology results and clinical follow-up. Univariate and multivariate logistic regression analyses were performed to evaluate the independent risk factors of metastatic LNs. According to the β coefficients of corresponding indicators in logistic regression analysis, a risk-scoring model was established. Receiver operating characteristic curve was applied to evaluate the predictive capability of model.

Results

Multivariate analysis showed that short axis >10 mm, distinct margin, absence of central hilar structure, presence of necrosis, nonhilar vascularity, and elastography score 4 to 5 were independent predictors of metastatic LNs. Both short axis and margin were scored 1 point, and the rest of independent predictors were scored 2 points. The combination of 3 EBUS modes had the highest area under the receiver operating characteristic and accuracy of 0.884 (95% confidence interval, 0.846-0.922) and 87.55%, respectively. The risk stratification was as follows: 0 to 2 points, malignancy rate of 11.11%, low suspicion; 3 to 10 points, malignancy rate of 86.77%, high suspicion.

Conclusions

The risk-scoring model based on EBUS multimodal imaging can effectively evaluate metastatic LNs in lung cancer patients to support clinical decision making.

A Nomogram to Predict Benign/Malignant Mediastinal Lymph Nodes Based on EBUS Sonographic Features

Background

Endobronchial ultrasound (EBUS) sonographic features help identify benign/malignant lymph nodes while conducting transbronchial needle aspiration (TBNA). This study aims to identify risk factors for malignancy based on EBUS sonographic features and to estimate the risk of malignancy in lymph nodes by constructing a nomogram.

Methods

1082 lymph nodes from 625 patients were randomly enrolled in training (n = 760) and validation (n = 322) sets. The subgroup of EBUS-TBNA postoperative negative lymph nodes (n = 317) was randomly enrolled in a training (n = 224) set and a validation (n = 93) set. Logistic regression analysis was used to identify the EBUS features of malignant lymph nodes. A nomogram was formulated using the EBUS features in the training set and later validated in the validation set.

Results

Multivariate analysis revealed that long-axis, short-axis, echogenicity, fusion, and central hilar structure (CHS) were the independent predictors of malignant lymph nodes. Based on these risk factors, a nomogram was constructed. Both the training and validation sets of 5 EBUS features nomogram showed good discrimination, with area under the curve values of 0.880 (sensitivity = 0.829 and specificity = 0.807) and 0.905 (sensitivity = 0.819 and specificity = 0.857). Subgroup multivariate analysis revealed that long-axis, echogenicity, and CHS were the independent predictors of malignancy outcomes of EBUS-TBNA postoperative negative lymph nodes. Based on these risk factors, a nomogram was constructed. Both the training and validation sets of 3 EBUS features nomogram showed good discrimination, with the area under the curve values of 0.890 (sensitivity = 0.882 and specificity = 0.786) and 0.834 (sensitivity = 0.930 and specificity = 0.636).

Conclusions

Our novel scoring system based on two nomograms can be utilized to predict malignant lymph nodes.

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.

Proposed quality indicators and recommended standard reporting items in performance of EBUS bronchoscopy: An official World Association for Bronchology and Interventional Pulmonology Expert Panel consensus statement

BACKGROUND

Since their introduction, both linear and radial endobronchial ultrasound (EBUS) have become an integral component of the practice of Pulmonology and Thoracic Oncology. The quality of health care can be measured by comparing the performance of an individual or a health service with an ideal threshold or benchmark. The taskforce sought to evaluate quality indicators in EBUS bronchoscopy based on clinical relevance/importance and on the basis that observed significant variation in outcomes indicates potential for improvement in health care outcomes.

METHODS

A comprehensive literature review informed the composition of a comprehensive list of candidate quality indicators in EBUS. A multiple-round modified Delphi consensus process was subsequently performed with the aim of reaching consensus over a final list of quality indicators and performance targets for these indicators. Standard reporting items were developed, with a strong preference for items where evidence demonstrates a relationship with quality indicator outcomes.

RESULTS

Twelve quality Indicators are proposed, with performance targets supported by evidence from the literature. Standardized reporting items for both radial and linear EBUS are recommended, with evidence supporting their utility in assessing procedural outcomes presented.

CONCLUSION

This statement is intended to provide a framework for individual proceduralists to assess the quality of EBUS they provide their patients through the identification of clinically relevant, feasible quality measures. Emphasis is placed on outcome measures, with a preference for consistent terminology to allow communication and benchmarking between centres.

Mediastinal Staging in Non-Small-Cell Lung Cancer: Saying Goodbye to Mediastinoscopy

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice.Accurate staging of the mediastinal lymph nodes in resectable non-small-cell lung cancer (NSCLC) is critically important to determine the overall stage of the tumor and guide subsequent management. The staging process typically begins with positron emission tomography (PET) or computed tomography imaging; however, imaging alone is inadequate, and tissue acquisition is required for confirmation of nodal disease. Mediastinoscopy was long considered the gold standard for staging of mediastinal lymph nodes, but, recently, endobronchial ultrasound-guided (EBUS) fine-needle aspiration (FNA) has become the standard of care. EBUS-FNA, in combination with supplementary technologies, such as intranodal forceps biopsy and esophageal ultrasonography, has a high sensitivity and specificity for the diagnosis of nodal metastases. EBUS-FNA is also capable of assessing N1 disease and obtaining adequate tissue for tumor genomic analysis to help guide treatment. In the case of negative findings on EBUS, a confirmatory video mediastinoscopy is still recommended by the European Society of Thoracic Surgeons guidelines. However, whether confirmatory mediastinoscopy is necessary is a matter of debate, and it is not commonly performed in North America. To address this question, Bousema and colleagues performed a randomized noninferiority trial to determine rates of unforeseen nodal metastases after EBUS alone versus EBUS with confirmatory mediastinoscopy in patients with resectable NSCLC. The authors concluded that EBUS alone is noninferior to EBUS with confirmatory mediastinoscopy. These findings affirm our current practice to forgo confirmatory mediastinoscopy after negative findings on EBUS.

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.

How I treat refractory/relapsed diffuse large B-cell lymphomas with CD19-directed chimeric antigen receptor T cells

Chimeric antigen receptor (CAR) T cells targeting CD19 represent a promising salvage immunotherapy for relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL), offering ~40% of long-term responses. In everyday clinical practice, haematologists involved in CAR T cell treatment of patients with R/R DLBCL have to deal with diagnostically complex cases and difficult therapeutic choices. The availability of novel immunotherapeutic agents for R/R DLBCL and recent advances in understanding CAR T-cell failure mechanisms demand a rational approach to identify the best choice for bridging therapy and managing post-CAR T-cell therapy relapses. Moreover, positron emission tomography/computerised tomography may result in false-positive interpretation, highlighting the importance of post-treatment biopsy. In this review, we discuss all above issues, presenting four instructive cases, with the aim to provide criteria and new perspectives for CAR T-cell treatment of DLBCL.

Prediction of malignancy in mediastinal lymph nodes during endobronchial ultrasound: A comparative validation study

Background

In this study, we aimed to compare the diagnostic performances of three existing prediction tools in visually identifying a malignant lymph node.

Methods

Between April 2016 and January 2021, a total of 827 lymph nodes of 259 patients (211 males, 48 females; mean age: 61.1±7.2 years; range, 41 to 79 years) who underwent endobronchial ultrasound procedure for diagnosis and/or staging of lung cancer and diagnosis of mediastinal lymphadenopathy of unknown origin were retrospectively analyzed. This external validation study was designed to compare the diagnostic yields of the prediction tools developed by Shafiek et al., Alici et al., and Canada Lymph Node Score (CLNS). Endobronchial ultrasoundguided transbronchial needle aspiration results and predictions were compared to gold-standard tool.

Results

Overall, endobronchial ultrasound-guided transbronchial needle aspiration had a sensitivity, specificity, positive and negative predictive value, and accuracy of 95.6%, 100%, 100%, 97.6%, and 98.4%, respectively. Diagnostic performances of proposed tools were quite remarkable. Among them, Alici algorithm had a higher sensitivity and negative predictive value, which were matched by excellent specificity and positive predictive value offered by CLNS ≥3 and Shafiek tool. The area under the curve value of CLNS ≥3 was higher than Shafiek tool and CLNS ≥2.

Conclusion

Conventional prediction tools relying on simple real-time sonographic features were found to be consistent by the means of diagnostic performance in this external validation dataset. Despite being inferior to cytology, their superior performance was proven with defined individual strengths and weaknesses.

Predicting Malignant Lymph Nodes Using a Novel Scoring System Based on Multi-Endobronchial Ultrasound Features

Endobronchial ultrasound (EBUS) features with B-, power/color Doppler, and elastography modes help differentiate between benign and malignant lymph nodes (MLNs) during transbronchial needle aspiration (TBNA); however, only few studies have assessed them simultaneously. We evaluated the diagnostic accuracy of each EBUS feature and aimed to establish a scoring system to predict MLNs. EBUS features of consecutive patients and final diagnosis per lymph node (LN) were examined retrospectively. In total, 594 LNs from 301 patients were analyzed. Univariable analyses revealed that EBUS features, except for round shape, could differentiate MLNs from benign LNs. Multivariable analysis revealed that short axis (>1 cm), heterogeneous echogenicity, absence of central hilar structure, presence of coagulation necrosis sign, and blue-dominant elastographic images were independent predictors of MLNs. At three or more EBUS features predicting MLNs, our scoring system had high sensitivity (77.9%) and specificity (91.8%). The area under the receiver operating curve (AUC) was 0.894 (95% confidence interval (CI): 0.868−0.920), which was higher than that of B-mode features alone (AUC: 0.840 (95% CI: 0.807−0.873)). The novel scoring system could predict MLNs more accurately than B-mode features alone. Multi-EBUS features may increase EBUS-TBNA efficiency for LN evaluation.

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.

Diagnostic value of endobronchial ultrasound elastography combined with rapid onsite cytological evaluation in endobronchial ultrasound-guided transbronchial needle aspiration

Background

Endobronchial ultrasound (EBUS) elastography has been used in EBUS-guided transbronchial needle aspiration (EBUS-TBNA) to identify malignant lymph nodes based on tissue stiffness. Rapid onsite cytological evaluation (ROSE) has been widely utilized for onsite evaluation of sample adequacy and for guiding sampling during EBUS-TBNA. The aim of this study was to investigate the diagnostic value of combined EBUS elastography and ROSE in evaluating mediastinal and hilar lymph node status.

Methods

Retrospective chart review was performed from December 2018 to September 2020. Patient demographics, EBUS elastography scores, and ROSE, pathologic, and clinical outcome data were collected. The EBUS elastography scores were classified as follows: Type 1, predominantly nonblue; Type 2, partially blue and partially nonblue; and Type 3, predominantly blue. A receiver operating characteristic curve was used to compare the sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio for evaluation of malignant lymph nodes among the EBUS elastography, ROSE, and EBUS combined with ROSE groups.

Results

A total of 245 patients (345 lymph nodes) were included. The sensitivity and specificity of the EBUS elastography group for the diagnosis of malignant lymph nodes were 90.51% and 57.26%, respectively. The sensitivity and specificity in the ROSE group were 96.32% and 79.05%, respectively. The sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of EBUS elastography combined with ROSE were 86.61%, 92.65%, 11.78, and 0.14, respectively, and the area under the curve was 0.942.

Conclusions

Combining EBUS elastography and ROSE significantly increased the diagnostic value of EBUS-TBNA in evaluating mediastinal and hilar lymph node status compared to each method alone.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01748-4.

Elucidating the Etiologies of 18F-fluorodeoxyglucose-Avid Mediastinal Lymph Nodes Among Cancer Patients in a Tuberculosis-Endemic Region Using Endobronchial Ultrasound

Background

Non-malignant conditions, including infections (such as tuberculosis [TB]), can mimic malignancy with regards to their uptake of 18F-fluorodeoxyglucose (¹⁸F-FDG) tracer utilized for positron emission tomography-computed tomography (PET-CT) scan, as part of the diagnostic and staging workup of cancer patients. This poses a diagnostic challenge, for which tissue sampling is decisive. In this study, we aimed to determine the underlying etiologies of ¹⁸F-FDG-avid mediastinal lymph nodes among cancer patients in a TB-endemic demographic using endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and the respective sensitivity and specificity of PET-CT and EBUS in diagnosing malignancy.

Methodology

In this retrospective cross-sectional study, we analyzed the data of all cancer patients with ¹⁸F-FDG-avid mediastinal lymphadenopathy on diagnostic PET imaging, who later underwent EBUS-TBNA between July 2013 and December 2018 at our center. Logistic regression analysis was used to determine the relative risk of lymph node characteristics with malignant TBNA cytology, based on which a risk stratification model was formulated.

Results

A total of 178 patients were included in this study, comprising predominantly males (60.7%). The primary malignancy was lung cancer in 33 (18.5%) patients, while 145 (81.5%) had non-lung cancer. A total of 214 ¹⁸F-FDG lymph nodes were sampled, out of which TBNA revealed malignant cytology in only 44 (20.6%). The final diagnosis was malignancy, TB, and sarcoidosis in 42 (23.6%), 16 (9%), and 12 (6.7%) patients, respectively. Among the remaining, 98 (55%) patients were determined to have only reactive lymphadenopathy, of which 24 (24.5%) had nodal anthracosis, while TBNA was inadequate for the diagnosis in 10 (5.6%) patients. An increased risk of malignancy was associated with the size of lymph node [odds ratio (OR): 1.58 (confidence interval (CI): 1.19, 2.11; p = 0.001], the standard uptake value (SUV) of the lymph node on PET-CT [OR: 1.30 (CI: 1.15, 1.45); p = 0.001], and with primary lung malignancy [OR: 4.44 (CI: 1.96, 10.06); p = 0.001]. At an SUV cut-off value of 6.0, PET-CT had the sensitivity, specificity, positive predictive value, and negative predictive value of 73%, 70%, 49.3%, and 91.8%, respectively, for diagnosing malignancy, while the same for EBUS was estimated to be 93.3%, 100%, 100%, and 97%, respectively.

Conclusions

In addition to TB, benign etiologies including nodal anthracosis and sarcoidosis predominate as causes of ¹⁸F-FDG-avid mediastinal lymphadenopathy in cancer patients of a TB-endemic demographic. The predictable risk of malignancy on PET imaging increases with nodal size, SUV, and lung primary malignancy; however, EBUS clearly demonstrates a higher sensitivity.

Patterns of nodal spread in stage III NSCLC: importance of EBUS-TBNA and 18F-FDG PET/CT for radiotherapy target volume definition

Purpose

The aim of this study was to compare the pattern of intra-patient spread of lymph-node (LN)-metastases within the mediastinum as assessed by ¹⁸F-FDG PET/CT and systematic endobronchial ultrasound-guided transbronchial-needle aspiration (EBUS-TBNA) for precise target volume definition in stage III NSCLC.

Methods

This is a single-center study based on our preceding investigation, including all consecutive patients with initial diagnosis of stage IIIA-C NSCLC, receiving concurrent radiochemotherapy (12/2011–06/2018). Inclusion criteria were curative treatment intent, ¹⁸F-FDG PET/CT and EBUS-TBNA prior to start of treatment. The lymphatic drainage was classified into echelon-1 (ipsilateral hilum), echelon-2 (ipsilateral LN-stations 4 and 7) and echelon-3 (rest of the mediastinum, contralateral hilum). The pattern of spread was classified according to all permutations of echelon-1, echelon-2, and echelon-3 EBUS-TBNA findings.

Results

In total, 180 patients were enrolled. Various patterns of LN-spread could be identified. Skip lesions with an involved echelon distal from an uninvolved one were detected in less than 10% of patients by both EBUS-TBNA and PET. The pattern with largest asymmetry was detected in cases with EBUS-TBNA- or PET-positivity at all three echelons (p < 0.0001, exact symmetry test). In a multivariable logistic model for EBUS-positivity at echelon-3, prognostic factors were PET-positivity at echelon-3 (Hazard ratio (HR) = 12.1; 95%-CI: 3.2–46.5), EBUS-TBNA positivity at echelon-2 (HR = 6.7; 95%-CI: 1.31–31.2) and left-sided tumor location (HR = 4.0; 95%-CI: 1.24–13.2). There were significantly less combined ipsilateral upper (LN-stations 2 and 4) and lower (LN-station 7) mediastinal involvements (16.8% of patients) with EBUS-TBNA than with PET (38.9%, p < 0.0001, exact symmetry test). EBUS-TBNA detected a lobe specific heterogeneity between the odds ratios of LN-positivity in the upper versus lower mediastinum (p = 0.0021, Breslow-Day test), while PET did not (p = 0.19).

Conclusion

Frequent patterns of LN-metastatic spread could be defined by EBUS-TBNA and PET and discrepancies in the pattern were seen between both methods. EBUS-TBNA showed more lobe and tumor laterality specific patterns of LN-metastases than PET and skipped lymph node stations were rare. These systematic relations offer the opportunity to further refine multi-parameter risk of LN-involvement models for target volume delineation based on pattern of spread by EBUS-TBNA and PET.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13014-021-01904-4.

N3 hilar sampling decision in the staging of mediastinal lung cancer

The guidelines [1–4] on invasive staging for lung cancer recommend endoscopic ultrasound-guided fine-needle aspiration over surgical staging in patients with a high suspicion of lymph node involvement, either by morphological criteria (>1 cm in short axis) on computed tomography (CT) or metabolic criteria on positron emission tomography (PET) uptake (standardised uptake value maximum (SUVmax) >2.5). This recommendation is also valid for a CT and PET negative mediastinum if there is a central tumour, N1 disease, a low uptake tumour or a T2 tumour (>3 cm).

There is insufficient evidence for the sampling of morphometabolically normal N3 hilar lymph nodeshttps://bit.ly/3gWcar7

An Artificial Intelligence Algorithm to Predict Nodal Metastasis in Lung Cancer

BACKGROUND

Endobronchial Ultrasound (EBUS) features have high accuracy for predicting lymph node (LN) malignancy. However, their clinical application remains limited due to high operator dependency. We hypothesized that an Artificial Intelligence algorithm (NeuralSeg) is capable of accurately identifying and predicting LN malignancy based on EBUS images.

METHODS

In the derivation phase, EBUS images were segmented twice by an endosonographer and used as controls in 5-fold cross-validation training of NeuralSeg. In the validation phase, the algorithm was tested on new images it had not seen before. Logistic regression and receiver operator characteristic curves were used to determine NeuralSeg's capability of discrimination between benign and malignant LNs, using pathologic specimens as gold standard.

RESULTS

In total, 298 LNs from 140 patients were used for derivation and 108 LNs from 47 patients for validation. In the derivation cohort, NeuralSeg was able to predict malignant LNs with an accuracy of 73.8% (95% CI: 68.4% to 78.7%). In the validation cohort, NeuralSeg had an accuracy of 72.9% (95% CI: 63.5% to 81.0%), a specificity of 90.8% (95% CI: 81.9% to 96.2%) and negative predictive value (NPV) of 75.9% (95% CI: 71.5% to 79.9%). NeuralSeg showed higher diagnostic discrimination during validation compared to derivation (c-statistic= 0.75 [95% CI: 0.65-0.85] vs c-statistic=0.63 [95% CI: 0.54-0.72]).

CONCLUSIONS

NeuralSeg is able to accurately rule out nodal metastasis and can possibly be used as an adjunct to EBUS when nodal biopsy is not possible or inconclusive. Future work to evaluate the algorithm in a clinical trial will be required.

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.

Endobronchial Ultrasound Staging of Operable Non-small Cell Lung Cancer: Do Triple-Normal Lymph Nodes Require Routine Biopsy?

BACKGROUND

Staging guidelines for lung cancer recommend endobronchial ultrasound (EBUS) and systematic biopsy of at least three mediastinal lymph node (LN) stations for accurate staging. A four-point ultrasonographic score (Canada Lymph Node Score [CLNS]) was developed to determine the probability of malignancy in each LN. A LN with a CLNS of < 2 is considered low probability for malignancy. We hypothesized that, in patients with cN0 non-small cell lung cancer, LNs with CLNS of < 2 may not require routine biopsy because they represent true node-negative disease.

RESEARCH QUESTION

Do LNs considered triple normal on CT scanning, PET scanning, and CLNS evaluation require routine biopsy?

STUDY DESIGN AND METHODS

LNs were evaluated for ultrasonographic features at the time of EBUS and the CLNS was applied. Triple-normal LNs were defined as cN0 on CT scanning (short axis, < 1 cm), PET scanning (no hypermetabolic activity), and EBUS (CLNS, < 2). Specificity and negative predictive value (NPV) were calculated against the gold standard pathologic diagnosis from surgically excised specimens.

RESULTS

In total, 143 LNs from 57 cN0 patients were assessed. Triple-normal LNs showed a specificity and NPV of 60% (95% CI, 51.2%-68.3%) and 93.1% (95% CI, 85.6%-97.4%), respectively. After pathologic assessment, only 5.6% (n = 8/143) of triple-normal nodes were proven to be malignant.

INTERPRETATION

At the time of staging for lung cancer, combining CT scanning, PET scanning, and CLNS criteria can identify triple-normal LNs that have a high NPV for malignancy. This raises the question of whether triple-normal LNs require routine sampling during EBUS and transbronchial needle aspiration. A prospective trial is required to confirm these findings.

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.

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.

A Prediction Model to Help with Oncologic Mediastinal Evaluation for Radiation: HOMER

Rationale: When stereotactic ablative radiotherapy is an option for patients with non–small cell lung cancer (NSCLC), distinguishing between N0, N1, and N2 or N3 (N2|3) disease is important.

Objectives: To develop a prediction model for estimating the probability of N0, N1, and N2|3 disease.

Methods: Consecutive patients with clinical-radiographic stage T1 to T3, N0 to N3, and M0 NSCLC who underwent endobronchial ultrasound–guided staging from a single center were included. Multivariate ordinal logistic regression analysis was used to predict the presence of N0, N1, or N2|3 disease. Temporal validation used consecutive patients from 3 years later at the same center. External validation used three other hospitals.

Measurements and Main Results: In the model development cohort (n = 633), younger age, central location, adenocarcinoma, and higher positron emission tomography–computed tomography nodal stage were associated with a higher probability of having advanced nodal disease. Areas under the receiver operating characteristic curve (AUCs) were 0.84 and 0.86 for predicting N1 or higher (vs. N0) disease and N2|3 (vs. N0 or N1) disease, respectively. Model fit was acceptable (Hosmer-Lemeshow, P = 0.960; Brier score, 0.36). In the temporal validation cohort (n = 473), AUCs were 0.86 and 0.88. Model fit was acceptable (Hosmer-Lemeshow, P = 0.172; Brier score, 0.30). In the external validation cohort (n = 722), AUCs were 0.86 and 0.88 but required calibration (Hosmer-Lemeshow, P < 0.001; Brier score, 0.38). Calibration using the general calibration method resulted in acceptable model fit (Hosmer-Lemeshow, P = 0.094; Brier score, 0.34).

Conclusions: This prediction model can estimate the probability of N0, N1, and N2|3 disease in patients with NSCLC. The model has the potential to facilitate decision-making in patients with NSCLC when stereotactic ablative radiotherapy is an option.

A novel online education module to teach clinicians how to correctly identify ultrasonographic features of mediastinal lymph nodes during endobronchial ultrasound

Background

Ultrasonographic features can be used to predict mediastinal lymph node malignancy during endobronchial ultrasonography. Despite the validity of using these features for this purpose, the features are not being widely used in clinical practice. This may be attributable to the absence of educational programs that teach clinicians how to identify the features. To address this knowledge gap, we developed an online educational module to teach clinicians how to correctly interpret ultrasonographic features.

Methods

The module was designed using corrective feedback and test-enhanced learning theories and distributed to clinicians in relevant specialties. The efficacy of the program was determined by comparing the percentages of correctly identified ultrasonographic features as each clinician progressed through the module. Participants were also asked to self-rate their confidence during the module. Analysis of variance was conducted, and a learning curve and descriptive statistics were generated.

Results

Twenty-two of the 29 participants (76%) completed the module. Analysis of variance indicated that the percentage of correctly identified features increased significantly as clinicians completed the module (p = 0.004); this finding is supported by the positive slope of the learning curve. Even though they initially reported some difficulty with identifying certain features, their confidence increased as they progressed through the module. When asked, 86% of participants reported that they found the educational module helpful and 90% reported that they would recommend it to others.

Conclusion

Participating clinicians were receptive to the interactive educational module. It enhances clinician skill and confidence in interpreting ultrasonographic features. The results of this study provide the foundation needed to test the validity of the educational module in clinical settings and to further explore clinician preferences for educational programs.

The Canada Lymph Node Score for prediction of malignancy in mediastinal lymph nodes during endobronchial ultrasound

OBJECTIVE(S)

During endobronchial ultrasound (EBUS) staging, ultrasonographic features can be used to predict mediastinal lymph node (LN) malignancy. We sought to develop the Canada Lymph Node Score a tool capable of predicting LN metastasis at the time of EBUS.

METHODS

Patients undergoing EBUS staging for lung and esophageal cancer were prospectively enrolled. Features were identified in real time by an endoscopist and video-recorded. Videos were sent to raters. Pathologic specimens from biopsies/surgical resections were used as the gold-standard reference test. Logistic regression, receiver operator characteristic curve, and Gwet's AC1 analyses were used to test the performance, discrimination, and inter-rater reliability, respectively.

RESULTS

In total, 300 LNs from 140 patients were analyzed by 12 endoscopists (raters) across 7 Canadian centers. Beta-coefficients from a multivariate regression model were used to create a 4-point score: short-axis diameter, margins, central hilar structure, and necrosis. The model showed good discriminatory power (c-statistic = 0.72 ± 0.04, 95% confidence interval [CI], 0.64-0.80; bias-corrected c-statistic: 0.66, 95% CI, 0.55-0.76). LNs scoring 3/4 or 4/4 had odds ratios of 15.17 (P < .0001) and 50.56 (P = .001) for predicting malignancy, respectively. Inter-rater reliability for a score ≥3 was 0.81 ± 0.02 (95% CI, 0.77-0.85).

CONCLUSIONS

The Canada Lymph Node Score is a 4-point score demonstrating excellent performance in identifying malignant LNs during EBUS. A cut-off of ≥3 may inform decision-making regarding biopsy, repeat biopsy, or mediastinoscopy if the initial results are inconclusive.

Methionyl-tRNA Synthetase is a Useful Diagnostic Marker for Lymph Node Metastasis in Non-Small Cell Lung Cancer

PURPOSE

Identification of lymph node (LN) metastasis in non-small cell lung cancer (NSCLC) is critical for disease staging and selection of therapeutic modalities. Sometimes it is not possible to obtain LN core tissue by endobronchial ultrasound-guided transbronchial needle aspirate (EBUS-TBNA), resulting in low diagnostic yield.

MATERIALS AND METHODS

In this study, 138 specimens were collected from 108 patients who underwent EBUS-TBNA under the suspicion of LN metastasis of NSCLC. Diagnostic yields of anti-CD45 and anti-methionyl-tRNA synthetase (MRS), immunofluorescent (IF) staining on cytology specimens were compared with those of conventional cytology and positron emission tomography-computed tomography (PET-CT).

RESULTS

MRS was strongly expressed in NSCLC cells metastasized to LNs, but weakly expressed in cells at the periphery of the LN germinal center. The majority of cells were CD20 positive, although a few cells were either CD3 or CD14 positive, indicating that CD45 staining is required for discrimination of non-malignant LN constituent cells from NSCLC cells. When the diagnostic efficacy of MRS/CD45 IF staining was evaluated using 138 LN cellular aspirates from 108 patients through EBUS-TBNA, the sensitivity was 76.7% and specificity was 90.8%, whereas those of conventional cytology test were 71.8% and 100.0%, respectively. Combining the results of conventional cytology testing and those of PET-CT showed a sensitivity and specificity of 71.6% and 100%, and the addition of MRS/CD45 dual IF data to this combination increased sensitivity and specificity to 85.1% and 97.8%, respectively.

CONCLUSION

MRS/CD45 dual IF staining showed good diagnostic performance and may be a good tool complementing conventional cytology test for determining LN metastasis of NSCLC.

Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration for Diagnosis and Staging of Lung Cancer

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS TBNA) is fundamental to the diagnosis of lung cancer, as many patients present with more advanced stages of lung cancer, with enlarged hilar and mediastinal lymph nodes. It also represents a way to sample pulmonary masses directly to make the diagnosis, whereby no other accessible tissue is present and the mass sits adjacent to a large central airway. Very importantly also, EBUS TBNA is the widely accepted first procedure in lung cancer staging. A combined procedure of EUS TBNA can be performed to improve diagnostic accuracy.

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.

Systematic Endobronchial Ultrasound-guided Mediastinal Staging Versus Positron Emission Tomography for Comprehensive Mediastinal Staging in NSCLC Before Radical Radiotherapy of Non-small Cell Lung Cancer: A Pilot Study

Despite known limitations of positron emission tomography (PET) for mediastinal staging of non-small cell lung cancer (NSCLC), radiation treatment fields are generally based on PET-identified disease extent. However, no studies have examined the accuracy of FDG-PET/CT on a per-node basis in patients being considered for curative-intent radiotherapy in NSCLC.In a prospective trial, patients with NSCLC being considered for definitive thoracic radiotherapy (± systemic chemotherapy) underwent minimally invasive systematic mediastinal evaluation with endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) following noninvasive staging with integrated PET-CT.Thirty patients underwent EBUS-TBNA, with TBNA performed from a mean 2.5 lymph node (LN) stations per patient (median 3, range 1-5). Discordant findings between PET-CT and EBUS-TBNA were observed in 10 patients (33%, 95% CI 19%-51%). PET-occult LN metastases were demonstrated by EBUS in 4 patients, whereas a lesser extent of mediastinal involvement, compared with FDG-PET, was demonstrated by EBUS in 6 patients, including 2 patients downstaged from cN3 to pN2. LNs upstaged by EBUS were significantly smaller than nodes downstaged by EBUS, 7.5 mm (range 7-9) versus 12 mm (range 6-21), P = 0.005.A significant proportion of patients considered for definitive radiotherapy (+/-chemotherapy) undergoing systematic mediastinal evaluation with EBUS-TBNA in this study have an extent of mediastinal NSCLC involvement discordant with that indicated by PET-CT. Systematic EBUS-TBNA may aid in defining the extent of mediastinal involvement in NSCLC patients undergoing radiotherapy. Systematic EBUS-TBNA has the potential to contribute significantly to radiotherapy planning and delivery, by either identifying occult nodal metastases, or demonstrating FDG-avid LNs to be disease-free.