Added value of endoscopic ultrasound to endobronchial ultrasound in non-small cell lung cancer staging

: Combining endoscopic ultrasound (EUS/EUS-B) and endobronchial ultrasound (EBUS) can improve diagnosis and accurate staging of non-small cell lung cancer (NSCLC). Guidelines recommend endoscopic techniques to sample suspicious nodules and masses. While EBUS is the preferred initial procedure of choice, EUS/EUS-B has been shown to have high sensitivity in sampling mediastinal and sub-diaphragmatic disease. Each procedure has unique implications but when combined, offers an additive benefit in the staging of malignant disease. Following EBUS with EUS/EUS-B during a diagnostic procedure increases overall sensitivity and negative predictive value, leading to improvement in time to diagnosis and staging, decreased health care costs, and improved patient comfort. The combined diagnostic sensitivity and yield are significantly increased compared to outcomes from a single procedure alone. Between EBUS and EUS/EUS-B, the mediastinum can technically be completely staged by minimally invasive techniques alone, reducing the need for surgical sampling. These endoscopic measures also have lower complication rates when compared to traditional surgical mediastinoscopy. In this paper, we will introduce EUS/EUS-B and describe the advantages of adding these procedures to EBUS. We will also describe biopsy techniques, comparison of these procedures, identification of lymph node landmarks, staging and restaging of the mediastinum, limitations, and future directions in endosonography.