Staging Non–Small Cell Lung Cancer: Endobronchial Ultrasound Versus Mediastinoscopy

Bronchoscopic staging of lung cancer

Advances in bronchoscopy have contributed valuable tools to the diagnosis and staging of lung cancer. Detection of lesions at the premalignant microscopic stage has become possible with autofluorescence bronchoscopy and narrow band imaging. Bronchoscopy also allows for sampling of visible intra-bronchial lesions and for transbronchial needle aspiration of lesions in pulmonary parenchyma. With endobronchial ultrasound guidance, real-time evaluation and biopsy of mediastinal and pulmonary lesions can be achieved, enabling accurate clinical and pathological T-staging and N-staging without the need for surgery. In combination with advanced imaging techniques, Navigational bronchoscopy allows for the targeting and biopsy of the most peripheral lesions that are located in the smallest airways. For patients in whom tumor genetics are important, bronchoscopic-guided transbronchial biopsy can provide sufficient material for molecular analysis. As minimally invasive technology continues to evolve and improve, bronchoscopic techniques are poised to continue to be essential for the diagnosis and staging of lung cancer.

The Techniques of Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive modality for mediastinal lymph node staging in lung cancer patients as well as for the diagnosis of mediastinal and hilar adenopathy. The high diagnostic yield of EBUS-TBNA for lymph node staging has been shown in systematic reviews and meta-analysis. It has attracted physicians and surgeons as an alternative modality to surgical biopsy for the assessment of patients with enlarged mediastinal and/or hilar lymph nodes. Cell blocks obtained by EBUS-TBNA can be applicable not only for pathologic diagnosis but also for further investigations such as immunohistochemistry and fluorescence in situ hybridization. In addition, samples obtained by EBUS-TBNA can also be used for molecular analysis. Unlike regular bronchoscopy, EBUS-TBNA uses the convex probe EBUS with an ultrasound probe on the tip of a flexible bronchoscope. It is important for the bronchoscopist to fully understand the mediastinal anatomy and be able to correlate it with the ultrasound images for a successful EBUS-TBNA. The dedicated transbronchial needle used for EBUS-TBNA is somewhat different from an ordinary transbronchial biopsy forceps. Training is mandatory for achieving high diagnostic yield without complications. The learning curve of EBUS-TBNA is different from each physician, and continuous training program will be needed for impartiality. This article explains the detailed techniques of EBUS-TBNA to master this innovative procedure.