The patients with thin-section contrast-enhanced CT scans within 2 months of the operation and with tumors with a consolidation/tumor ratio of ≥ 0.5 were evaluated. To match the number of the mediastinal node-negative group with that of the node-positive group, the latest 94 N0-1 patients were included. Among them, 94 patients had pathologically proven N2 disease, and 666 patients had pathologically proven N0 or N1 disease (mediastinal node negative). Their efficacies were compared with those evaluated using 2D-CT analysis, short-axis diameter, and the short-axis/long-axis ratio.īetween January 2012 and December 2021, 750 patients underwent pulmonary lobectomy or pneumonectomy with mediastinal lymph node dissection at the University of Tsukuba Hospital. The sphericity and volume of lymph nodes were evaluated using 3D-CT analysis. The aim of the present study was to evaluate the efficacy of 3D morphologic analysis to predict lymph node metastasis. We evaluated lymph node morphology using 3D-CT and introduced a novel index, sphericity, to evaluate the shape of lymph nodes sterically. Therefore, 3D-CT analysis could evaluate lymph node morphology more precisely. Because lymph nodes are three-dimensional (3D) objects and could be irregularly shaped in any direction, analysis using only axial sections could miss the features of a lymph node. However, the reported short-axis/long-axis ratio obtained on CT was analyzed using only axial sections. Regarding shape, the short-axis/long-axis ratio established for superficial lymph nodes using ultrasound sonography was reported in a study of CT of lung cancer patients. Regarding size, in addition to the prevalently used short-axis diameter, volume was reported as a useful predictor of metastasis. On the other hand, it was reported that metastatic lymph nodes tended to be more spherical than nonmetastatic ones, indicating that in addition to the size, the shape of lymph nodes is important in predicting metastasis. The short-axis diameter of relatively small metastatic lymph nodes could be smaller than 1 cm, which explains the limited sensitivity of the size criteria. However, these guidelines describe the size criterion only in terms of the short-axis diameter of lymph nodes shown on CT and, therefore, did not provide the required accuracy. The current guidelines (American Thoracic Society, American College of Clinical Pharmacy, and European Society of Thoracic Surgery) recommend CT for preoperative nodal evaluation. The size criterion using CT-ie, a lymph node with a short-axis diameter greater than or equal to 1 cm is regarded as metastasis -has been mostly used since the 1980s for predicting mediastinal lymph node metastasis. Computed tomography (CT) has been used as the initial imaging modality for diagnosis and for staging of lymph node metastasis. Nodal staging is an important factor in predicting prognosis and deciding appropriate treatments. Lung cancer is the leading cause of cancer death despite advances in treatment, and its prognosis remains insufficient. Our method for predicting lymph node metastasis based on sphericity of lymph nodes with a short-axis diameter ≥ 5 mm could do so with higher sensitivity than the conventional method, and with acceptable specificity. Conclusionīy using 3D-CT analysis to examine sphericity, we showed that metastatic lymph nodes became spherical. For lymph nodes with a short-axis diameter ≥ 5 mm, sphericity ≥ 0.60 identified metastasis with 84.1% sensitivity and 89.3% specificity. 0.60, p < 0.001) than those of nonmetastatic lymph nodes. Metastatic lymph nodes had a larger short-axis diameter (average: 8.2 mm vs. Each parameter was obtained and evaluated for ability to predict metastasis. The sphericity of the dissected station lymph nodes, which represents how close the node is to being a true sphere, was evaluated along with the diameter and volume. We reviewed the cases of 66 patients with N2 disease and of 68 patients with N0-1 disease who underwent lobectomy with mediastinal dissection between January 2012 and December 2021. We introduced sphericity as a criterion for evaluating morphologic differences between metastatic and nonmetastatic nodes. Although prevalently used, evaluation of lymph nodes is not always reliable. The presence of mediastinal lymph node metastasis is important because it is related to the treatment and prognosis of lung cancer.

Shotty lymph node surgery