Representativeness of nodal sampling with endobronchial ultrasonography in non-small-cell lung cancer staging

Confirmatory Mediastinoscopy after Negative EBUS-TBNA for Mediastinal Staging of Lung Cancer: Systematic Review and Meta-analysis

RATIONALE

Current guidelines of non-small cell lung cancer (NSCLC) mediastinal staging recommend starting invasive staging with endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). However, the indication to confirm a negative result of EBUS-TBNA by means of video-assisted mediastinoscopy (VAM) prior to resection differs in every guideline.

OBJECTIVE

Our aim was to evaluate the current evidence regarding the added value of confirmatory VAM after a negative EBUS-TBNA for mediastinal staging in patients with NSCLC.

METHODS

Systematic searches of studies on EBUS-TBNA for NSCLC mediastinal staging with or without confirmatory VAM but with surgical confirmation of negative results were conducted in accordance with PRISMA statement in PubMed, SCOPUS, Cochrane and Guidelines from 2005 through November 2021. In the meta-analysis the sensitivity of confirmatory VAM after a negative EBUS-TBNA, the sensitivity and negative predictive value (NPV) of the combination EBUS-TBNA plus confirmatory VAM, alongside the number of confirmatory VAM required to detect additional N2/3 disease (number needed to treat [NNT]), in patients with a previous negative EBUS-TBNA were estimated.

RESULTS

5412 articles were found, of which 29 studies were included. Random effects meta-analysis showed a sensitivity of 66.9% (95% CI: 55.8%-77.1%) for confirmatory VAM, and 96.7% (95% CI: 95.1%- 98%) for the combination EBUS-TBNA plus confirmatory VAM. NPV in studies with confirmatory VAM increased of 79.2% (95% CI: 71.4%-86.1%) for EBUS-TBNA alone to 91.8% (95% CI: 87.1%-95.5%) for EBUS-TBNA plus confirmatory VAM. The NNT of confirmatory VAM in patients with a previous negative EBUS-TBNA was 23.8 (95% CI: 19.3-31.2) CONCLUSIONS: Confirmatory VAM after negative EBUS-TBNA reduces the rate of unforeseen N2/3 disease, but with a high NNT, and should be recommended only to certain cases yet to be defined.

Systematic Compared With Targeted Staging With Endobronchial Ultrasound in Patients With Lung Cancer

BACKGROUND

To evaluate the accuracy of systematic mediastinal staging by endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) (sampling of all visible nodes measuring ≥5 mm from stations N3 to N1 regardless of their positron emission tomography/computed tomography [PET/CT] features) and compare this staging approach with targeted EBUS-TBNA staging (sampling only 18F-fluorodeoxyglucose [FDG]-avid nodes) in patients with N2 non-small cell lung cancer on PET/CT.

METHODS

Retrospective study of 107 patients who underwent systematic EBUS-TBNA mediastinal staging. The results were compared with those of a hypothetical scenario where only FDG-avid nodes on PET/CT would be sampled.

RESULTS

Systematic EBUS-TBNA sampling demonstrated N3 disease in 3 patients, N2 disease in 60 (42 single-station or N2a, 18 multiple-station or N2b) and N0/N1 disease in 44. Of these 44, 7 underwent mediastinoscopy, which did not show mediastinal disease; 6 of the 7 proceeded to lung resection, which also showed no mediastinal disease. Thirty-four N0/N1 patients after EBUS-TBNA underwent lung resection directly: N0/N1 was found in 30 and N2 in 4 (1 N2b with a PET/CT showing N2a disease, 3 N2a). Sensitivity, specificity, negative predictive value, positive predictive value, and overall accuracy of systematic EBUS-TBNA were 94%, 100%, 90%, 100% and 96%, respectively. Compared with targeted EBUS-TBNA, systematic EBUS-TBNA sampling provided additional important clinical information in 14 cases (13%): 3 N3 cases would have passed unnoticed, and 11 N2b cases would have been staged as N2a.

CONCLUSIONS

In clinical practice, systematic sampling of the mediastinum by EBUS-TBNA, regardless of PET/CT features, is to be recommended over targeted sampling.

When Should Negative Endobronchial Ultrasonography Findings be Confirmed by a More Invasive Procedure?

The treatment of non-small cell lung cancer is largely dependent on accurate staging in order to determine appropriate therapy. Despite advances in imaging, such as computed tomography and positron emission tomography, invasive mediastinal staging is frequently needed to rule out mediastinal involvement prior to curative-intent stereotactic ablative radiotherapy or surgical resection. Surgical mediastinal staging with mediastinoscopy, or anterior mediastinotomy, were traditionally considered the gold standard for invasive mediastinal staging. Endobronchial and endoscopic ultrasound have emerged as modern techniques that are being used as first-line options instead of surgical staging. As experience is gained with these newer techniques, the need for confirmatory surgical staging continues to diminish. This article addresses the situations in which negative results should be confirmed by a more invasive procedure.

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.

Endobronchial ultrasound-guided transbronchial needle aspiration in the staging of lung cancer patients

Objective:

Mediastinoscopy as diagnostic procedure for evaluation of mediastinum in patients with non-small-cell lung cancer has long been considered the reference standard. However, less invasive method has occurred. Endobronchial ultrasound–guided transbronchial needle aspiration came into widespread use and has resulted in controversy as to whether it is a good replacement for mediastinoscopy. We chose to demonstrate the usefulness of endobronchial ultrasound–guided transbronchial needle aspiration in evaluating the mediastinum in patients with non-small-cell lung cancer.

Material and methods:

Over a 48-month period, 1841 patients underwent endobronchial ultrasound–guided transbronchial needle aspiration at our healthcare centre. In all patients, 2964 biopsies from the lymph node group N2 and 783 from group N1 were taken. The mean short axis of the lymph nodes biopsied was 2.0 (range: 0.6–2.6). The mean number of lymph node stations biopsied per patient was 2.6. Patients with a negative result of endobronchial ultrasound–guided transbronchial needle aspiration underwent mediastinoscopy. All patients with a negative result in endobronchial ultrasound–guided transbronchial needle aspiration and mediastinoscopy underwent surgical resection with lymph node sampling.

Results:

The metastases to lymph nodes N2/N3 and N1 were found in 1111 (60.3%) and 199 (9.3%), respectively. Mediastinoscopy was performed in 730 patients with a positive result in 83 (11.4%) patients. In the group of operated patients, metastatic N1 disease was found in 264 (14.1%). In the group of the operated patients, mediastinal involvement of disease (N2) was found in 30 patients (4.5%). The sensitivity, negative predictive value and diagnostic accuracy for hilar lymph node staging for endobronchial ultrasound–guided transbronchial needle aspiration were 57%, 96% and 96%, respectively. The sensitivity, negative predictive value and diagnostic accuracy per patient for mediastinal lymph node staging for endobronchial ultrasound–guided transbronchial needle aspiration and mediastinoscopy were 91%, 85%, 93% and 73%, 95.5%, 97%, respectively. The specificity and positive predictive value of both tests were 100%.

Conclusion:

The clinical usefulness of endobronchial ultrasound–guided transbronchial needle aspiration is undeniable according to diagnostic performance data. Endobronchial ultrasound–guided transbronchial needle aspiration should be considered complementary to mediastinoscopy in the evaluation of patients with radiographically abnormal mediastinum.

Mediastinal staging in daily practice: endosonography, followed by cervical mediastinoscopy. Do we really need both?

OBJECTIVES

In patients with lung cancer, endosonography has emerged as a minimally invasive method to obtain cytological proof of mediastinal lymph nodes, suspicious for metastases on imaging. In case of a negative result, it is currently recommended that a cervical mediastinoscopy be performed additionally. However, in daily practice, a second procedure is often regarded superfluous. The goal of our study was to assess the additional value of a cervical mediastinoscopy, after a negative result of endosonography, in routine clinical practice.

METHODS

In a retrospective cohort study, the records of 147 consecutive patients with an indication for mediastinal lymph node staging and a negative result of endosonography were analysed. As a subsequent procedure, 124 patients underwent a cervical mediastinoscopy and 23 patients were scheduled for an intended curative resection directly. The negative predictive value (NPV) for both diagnostic procedures was determined, as well as the number of patients who needed to undergo a mediastinoscopy to find one false-negative result of endosonography (number needed to treat (NNT)). Clinical data of patients with a false-negative endosonography were analysed.

RESULTS

When using cervical mediastinoscopy as the gold standard, the NPV for endosonography was 88.7%, resulting in a NNT of 8.8 patients. For patients with fluoro-2-deoxyglucose positron emission tomography positive mediastinal lymph nodes, the NNT was 6.1. Overall, a futile thoracotomy could be prevented in 50% of patients by an additional mediastinoscopy. A representative lymph node aspirate, containing adequate numbers of lymphocytes, did not exclude metastases.

CONCLUSIONS

In patients with a high probability of mediastinal metastases, based on imaging, and negative endosonography, cervical mediastinoscopy should not be omitted, not even when the aspirate seems representative.