Mediastinal staging of NSCLC with endoscopic and endobronchial ultrasound

Abstract

Mediastinal staging of non-small-cell lung cancer (NSCLC) is of paramount importance. It distinguishes operable from inoperable disease, guides prognosis and allows accurate comparison of outcomes in clinical trials. Noninvasive imaging modalities for mediastinal staging include CT, PET and integrated PET-CT. Mediastinoscopy is considered the current gold standard; however, each of these techniques has limitations in sensitivity or specificity. These inadequacies mean that 10% of operations performed with curative intent in patients with NSCLC are futile, owing to inaccurate locoregional lymph-node staging. Endoscopic and endobronchial ultrasound-guided mediastinal lymph-node aspiration are important and promising innovative techniques with reported sensitivities and specificities higher than standard investigations. The role of these techniques in mediastinal lymph-node staging is evolving rapidly and early data suggest that they may diminish the need for invasive surgical staging of the mediastinum. Furthermore, these are outpatient procedures that do not require general anesthesia and may be combined safely in the same sitting, for optimal accuracy of mediastinal staging. We propose a new algorithm for the diagnosis and staging of NSCLC, based on the current evidence, which incorporates endoscopic and endobronchial ultrasound as a first investigation after CT in patients with intrathoracic disease.

Figures

Figure 1

Mediastinal lymph node stations, according to American Thoracic Society Regional Lymph Node Station criteria. © 1997 American College of Chest Physicians. Reproduced with permission from the American College of Chest Physicians via the Copyright Clearance Center.

Figure 2

Devices used in endoscopic and endobronchial ultrasound. Endoscopic ultrasound probe (left) and endobronchial ultrasound scope (right).

Figure 3

An ultrasonographic image obtained during endobronchial ultrasound-guided transbronchial needle aspiration. Abbreviation: LN, lymph node.

Figure 4

Novel diagnostic and staging algorithm for patients with suspected non-small-cell lung cancer, which incorporates endobronchial ultrasound-guided transbronchial needle aspiration, endoscopic ultrasound-guided fine-needle aspiration or the combined procedure as a first test after CT. Abbreviations: EBUS-TBNA, endobronchial ultrasound-guided transbrachial needle aspiration; EUS-FNA, endoscopic ultrasound-guided fine-needle aspiration; MLN, mediastinal lymph node.