Objective: The purpose of our study was to compare the diagnostic efficacies of helical dynamic CT and integrated PET/CT for the prediction of mediastinal nodal metastasis in stage T1 non-small cell lung cancer (NSCLC).
Materials and methods: One hundred forty-three patients with stage T1 NSCLC underwent both helical dynamic CT and integrated PET/CT followed by surgical nodal staging. In helical dynamic CT, patients were regarded to have stage N2 disease when a nodule showed a peak enhancement > or = 110 H or a net enhancement > or = 60 H. In integrated PET/CT, nodes were regarded as positive for malignancy when they showed > or = 3.5 in maximum standardized uptake value with a discrete margin and more 18F-FDG uptake than mediastinal structures. Sensitivities, specificities, and accuracies for mediastinal nodal metastasis detection were compared for helical dynamic CT and integrated PET/CT using the McNemar test.
Results: Of the 143 patients, 34 (24%) had positive mediastinal nodes. The sensitivity, specificity, and accuracy for mediastinal nodal metastasis prediction on helical dynamic CT were 65% (22 of 34 patients), 89% (97 of 109), and 83% (119 of 143), respectively, whereas those on integrated PET/CT were 56% (19 of 34), 100% (109 of 109), and 90% (128 of 143). The p values were 0.664, < 0.001, and 0.015.
Conclusion: In stage T1 NSCLC, contrast-enhanced helical dynamic CT better predicts, but not significantly so, mediastinal nodal metastasis than PET/CT, whereas PET/CT shows perfect specificity and higher accuracy than helical dynamic CT.