Quantitative Volumetric CT-Histogram Analysis in N-Staging of 18F-FDG–Equivocal Patients with Lung Cancer

Lung cancer often coexists with acute and chronic lung diseases such as chronic obstructive pulmonary disease. Therefore, medi-astinal lymph nodes may be false-positive on 18F-FDG PET because of the inflammatory disease alone. Nevertheless, 18F-FDG PET/CT is the primary imaging modality used for staging patients with lung cancer, including nodal status. The purpose of this study was to evaluate whether volumetric CT histogram analysis can improve the characterization of lymph nodes on PET/CT staging of patients with lung cancer. Methods: Sixty histologically proven lymph nodes of 45 patients aged 43–76 y diagnosed with lung cancer were inves-tigated. 18F-FDG PET/CT, contrast-enhanced CT, and nonen-hanced CT were performed before surgery or biopsy as part of the clinical staging procedure. Lymph nodes were analyzed on the basis of the 18F-FDG standardized uptake value and volumetric CT histogram analysis. These findings were correlated to the gold stan