Evolving role of interventional pulmonology in the interdisciplinary approach to the staging and management of lung cancer: bronchoscopic mediastinal staging of lung cancer.

Mediastinal lymph node involvement is present in 26\%-38\% of patients with non-small-cell lung cancer at the time of diagnosis, and it is often the most significant factor in determining surgical resectability. Complete and accurate mediastinal staging of lung cancer is essential for determining prognosis and for guiding optimal treatment strategies. Computed tomography and positron emission tomography are the most widely used noninvasive means for mediastinal staging in lung cancer. However, based on their reported specificities, computed tomography and positron emission tomography findings should be verified by cytohistologic sampling. In recent decades, the technique of transbronchial needle aspiration (TBNA) has been developed, permitting the bronchoscopist to obtain cytohistologic material from the hilar and mediastinal lymph nodes adjacent to the tracheobronchial wall. The technique of TBNA has a great specificity, is safe and cost-effective compared with surgical methods, and can be performed during the initial diagnostic bronchoscopy. Transbronchial needle aspiration sensitivity is 76\%-78\% but is highly influenced by several factors. Endobronchial ultrasound has been proposed as a means for improving TBNA sensitivity. Recently, a new type of bronchoscope with a built-in convex ultrasound probe directly attached to the tip has been developed to guide TBNA under real-time imaging. Reports on this innovative technique reveal a sensitivity of 94\%-95.7\%, which is superior to the reported sensitivity of surgical methods. However, ultrasound-guided TBNA and traditional TBNA should be considered complementary techniques, because their integration is likely to become the optimal staging strategy for patients with lung cancer.