Image-guided fine needle aspirate strategies for staging of lung cancer

Image-guided transthoracic, bronchoscopic, and endoscopic ultrasound fine needle aspiration (FNA) greatly facilitates lung cancer staging by having the potential to precisely biopsy lung lesions and virtually all medi-astinal lymph node stations. Imaging modalities alone, including chest x-ray, computed tomography (CT), magnetic resonance imaging, and positron emission tomography identify lesions suspicious for cancer but cannot make a tissue diagnosis. We describe an algorithm for the diagnosis and tumor-node-metastasis staging of lung cancer that uses procedures with the least invasiveness and cost with the highest diagnostic yields. For the anterior mediastinum, fluoroscopic-, ultrasound-, or CT-guided transthoracic FNA (which has a greater yield than bronchoscopy and is less invasive than mediastinoscopy) should be the primary technique for lymph node sampling. In the middle mediastinum, CT-guided transthoracic FNA is preferred for all nodal stations except subcarinal. Endoscopic ultrasound-guided FNA (EUS-FNA), which enables real-time biopsies within 5 cm of the esophagus, is preferred for sampling subcarinal and posterior mediastinal nodes because the yield is similar to CT-guided transthoracic FNA, with minimal risk of pneumothorax. The posterior mediastinum is also accessed by fluoroscopic- or CT-guided transthoracic FNA or video-assisted thoracic surgery. Sampling of the aorticopulmonary window depends on lymph node size; if the nodes are large enough to displace the aortic arch and pulmonary vein, then EUS-FNA is attempted, and if the nodes are not sufficiently enlarged, CT-guided transthoracic FNA should be performed prior to thoracoscopy or thoracotomy.