ABSTRACT
I. Introduction Lung cancer is the leading cause of cancer-related death in the Western world (1). Accurate staging is important to not only determine the prognosis but also decide the most suitable treatment plan for both operable and inoperable patients with non-small cell lung cancer (NSCLC) (1). Noninvasive imaging techniques such as computed tomography (CT) and positron emission tomography (PET) are inaccurate in the diagnosis of mediastinal lymph node metastasis (2). The sensitivity and specificity of CT for identifying mediastinal lymph node metastasis are 51% (range: 47-54%) and 85% (range: 84-88%), respectively; thus, CT has limited ability to either rule in or exclude mediastinal metastasis (2). PET scanning is more accurate than CT scanning, with a pooled sensitivity and specificity of 74% (range: 69-79%) and 85% (range: 82-88%), respectively (2). Furthermore, distant metastasis can be detected by PET scanning. With either CT or PET, abnormal findings must be confirmed by tissue biopsy. Surgical staging by mediastinoscopy, the gold standard for mediastinal staging, has a high sensitivity (80%) and specificity (100%) (3). The false-negative rate of mediastinoscopy is approximately 10% (3) with even lower rates with video-mediastinoscopy (7%). However, it is an invasive procedure that requires general anesthesia. Complications cannot be ignored.
