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Surgical resection is the accepted standard of care for patients with non-small cell lung cancer (NSCLC). Several imaging modalities play central roles in the detection and staging of the disease. The aim of this review is to evaluate the utility of computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET) and PET/CT for NSCLC staging. Radiographic staging refers to the use of CT as a non-invasive diagnostic technique. However, while the vast majority of patients undergo only CT, CT is a notoriously inaccurate means of tumor and nodal staging in many situations. PET/CT clearly improves the staging, particularly nodal staging, compared to CT or PET alone. In addition, as a result of the increased soft-tissue contrast, MRI is superior to CT for distinguishing between tissue characteristics. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), which is a minimally invasive technique, also has pathological diagnostic potential. Extensive research and the resultant improvements in the understanding of genetics, histology, molecular biology and oncology are transforming our understanding of lung cancer, and it is clear that imaging modalities such as CT, MRI, PET and PET/CT will have an important role in its preoperative management. However, thoracic surgeons should also be aware of the limitations of these techniques. [ABSTRACT FROM AUTHOR]

Purpose: Lymphatic spread of lung carcinoma to the mediastinum is a key determinant of prognosis. The lymph flow often carries metastases from the pulmonary segment directly into the mediastinal lymph nodes, without passing through the hilar nodes. This phenomenon is termed as 'skip metastasis.' This study investigated the subpleural lymphatic flow to the mediastinum using indocyanine green (ICG) with a near-infrared fluorescence imaging system. Methods: Seventeen patients with lung cancer were enrolled in this study. A 0.3 ml sample of solution containing the fluorescent dye ICG (5 mg/ml) was injected into subpleural sites near the primary tumor. Fluorescence imaging was used to monitor the flow of ICG-containing lymph from the injection site for 5 min. The relationship between the anatomical segment of the primary tumor and the lymphatic flow was assessed. Results: The lymphatic vessels draining from the injection site were revealed by the bright ICG fluorescence in 14 of the patients (82.4 %). A direct lymphatic flow to the mediastinum was confirmed in 3 of those 14 (21.4 %). Conclusions: These findings confirm the direct flow of lymph to the mediastinum without passage through the hilum pulmonis intraoperatively. These preliminary results may provide a valuable clue for further investigations of the mechanisms underlying skip metastasis. [ABSTRACT FROM AUTHOR]

Purpose: The criteria for the diagnosis of lymph node metastasis (LNM) in non-small cell lung cancer were investigated using helical computed tomography (hCT). The conventional criterion (1-cm short axis threshold) is generally accepted; however, this criterion is based on conventional CT. New criteria for LNM were investigated because the resolution of hCT is better than that of conventional CT. Methods: Ninety-seven NSCLC patients examined with hCT were enrolled. Both the long axis (LA) and short axis (SA) of the nodes were measured using hCT. Results: Based on the receiver operating characteristic curves, the thresholds that gave optimal sensitivity and specificity for LNM were 13 mm for LA and 9 mm for SA. The LNM diagnosis was re-evaluated using the combination of cutoff values. When the LA was ≥13 mm and the SA was ≥9 mm, the sensitivity, specificity, and accuracy were 56.3%, 92.1%, and 88.1%, respectively. When the LA was ≥13 mm or SA was ≥9 mm, sensitivity, specificity, and accuracy were 75.0%, 74.7%, and 74.7%, respectively. These values were not so different from the conventional criterion recalculated from these data. Conclusion: The new criteria are considered to be useful for making a LNM diagnosis. The conventional criteria for the LNM diagnosis might therefore be applicable even for hCT. [ABSTRACT FROM AUTHOR]