Adenocarcinoma with BAC Features Presented as the Nonsolid Nodule Is Prone to Be False-Negative on 18F-FDG PET/CT

PURPOSE The present study investigated which type of adenocarcinoma with BAC features was prone to be false-negative on 18F-FDG PET/CT. MATERIALS AND METHODS A retrospective study was performed on 51 consecutive patients with localized adenocarcinoma with BAC features. CT and PET were assessed for lesion size, GGO percentage, and SUVmax. Lesions with FDG uptake the same as or more than mediastinal blood-pool activity were considered as PET-positive. RESULTS Of the 51 cases, 19.6% presented as pure GGO nodules, 31.4% as mixed nodules, and 49.0% as solid nodules. None of the pure GGO nodules was 18F-FDG avid, compared with 37.5% of mixed nodules and 96.0% of solid nodules (χ2=31.55, P=0.000). In the mixed nodule group, SUVmax was negatively correlated with GGO percentage (r=-0.588; P=0.021). The positive detection rate of 18F-FDG PET/CT was 50.0%, 55.6%, and 100% in tumors 1.1-2.0 cm, 2.1-3.0 cm, and >3.0 cm in diameter, respectively (χ2=5.815, P=0.055). General linear model factor analysis showed that the GGO was an important factor contributing to false-negative PET/CT results (F=23.992, P=0.000), but lesion size was not (F=0.602, P=0.866). CONCLUSIONS The present study indicated that the adenocarcinoma with BAC features presented as nonsolid nodule is prone to be false negative on 18F-FDG PET/CT.