Risk factors for mediastinal lymph node metastasis in non-small-cell lung cancer by PET/CT.

OBJECTIVE

The aim of this study was to investigate the relationship between mediastinal lymph node metastasis based on fluorine-18 fluorodeoxyglucose ((18)F-FDG) PET/computed tomography (PET/CT) of the primary tumor and various clinical indexes to determine the risk factors for malignant lymph nodes in non-small-cell lung cancer (NSCLC).

MATERIALS AND METHODS

A total of 130 patients with histologically proven NSCLC who had not received any therapy underwent (18)F-FDG PET/CT for staging. The relationship between node metastasis, sex, age, smoking status, primary tumor maximum standardized uptake value (SUV(max)), size, pathological type, and differentiation was studied by univariate analyses, and risk factors for nodal metastasis in NSCLC were assessed by multivariate logistic regression.

RESULTS

Of the 130 patients, 68 were seen to have nodal metastasis on histological analysis. Nodal metastasis was correlated with SUV(max), size, and differentiation of primary lung lesions (P<0.05), and all the other factors were nonsignificant (P>0.05). On multivariate logistic regression analysis, the only independent factor was SUV(max) of the primary tumor, and the optimal cutoff value was 9.3 (sensitivity: 75.41%, 95% confidence interval: 62.7-85.5; specificity: 54.41%, 95% confidence interval: 41.9-66.5).

CONCLUSION

The mediastinal lymph node metastasis ratio was correlated with SUV(max), size, and differentiation in primary lung lesions. SUV(max) was the only independent predictor of lymph node metastasis in NSCLC. Video Abstract: http://links.lww.com/NMC/A22.