A narrative review of the role of endoscopic ultrasound (EUS) in lung cancer staging

Lung cancer is one of the most common solid malignant disease and an accurate staging is required for planning the most appropriate treatment. Surgery or local radiotherapy are the elective treatment for localized disease, however, the presence of mediastinal malignant lymph nodes can affect the role of surgery as a first-line therapy and a chemotherapy and/or radiotherapy treatment are recommended. Currently endoscopic ultrasound (EUS) in the mediastinum has brought the important advantage of a minimal-invasive diagnostic approach for the diagnosis and staging of malignant conditions, having the possibility of sampling lesions or lymph nodes in real-time. EUS' diagnostic capabilities have increased over time and currently it represents an excellent approach for the staging of lung cancer, especially combined to endobronchial ultrasound (EBUS). Last generation EUS equipments (echoendoscopes, ultrasound processors, needles) and tools [contrast-enhanced EUS (CH-EUS), elastography] can help the endosonographer during the ultrasound evaluation and they can increase the accuracy of lung cancer staging. A systematic method of evaluation of all the visible lymph nodes stations is fundamental to complete the lung cancer staging, as well as a correct endoscopic room organization of the equipments, healthcare personnel and devices.