Minimally Invasive Mediastinal Staging of Non-Small-Cell Lung Cancer: Emphasis on Ultrasonography-Guided Fine-Needle Aspiration

Background: Mediastinal staging in patients with non-small-cell lung cancer (NSCLC) is crucial in dictating surgical vs nonsurgical treatment. Cervical mediastinoscopy is the "gold standard" in mediastinal staging but is invasive and limited in assessing the posterior subcarinal, lower mediastinal, and hilar lymph nodes. Less invasive approaches to NSCLC staging have become more widely available. Methods: This article reviews several of these techniques, including noninvasive mediastinal staging of NSCLC, endobronchial ultrasound (EBUS) and fine-needle aspiration (FNA), endoscopic ultrasound (EUS) and FNA, and the combination of EBUS/EUS. Results: Noninvasive mediastinal staging with computed tomography and positron-emission tomography scans has significant false-negative and false-positive rates and requires lymph node tissue confirmation. FNA techniques, with guidance by EBUS and EUS, have become more widely available. The combination of EBUS-FNA and EUS-FNA of mediastinal lymph nodes can be a viable alternative to surgical mediastinal staging. Current barriers to the dissemination of these techniques include initial cost of equipment, lack of access to rapid on-site cytology, and the time required to obtain sufficient skills to duplicate published results. Conclusions: Within the last decade, these approaches to NSCLC staging have become more widely available. Continued study into these noninvasive techniques is warranted.