PET morphology helps distinguish solitary and solid pulmonary tuberculosis from non-small cell lung cancer

Solitary and solid pulmonary tuberculosis (PTB) and non-small cell lung cancer (NSCLC) can present overlapping imaging features, causing diagnostic dilemmas. Hence, this study aimed to identify positron emission tomography (PET) morphological features derived from fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) images for a better differential diagnosis.

Clinical records and ¹⁸F-FDG PET/CT images of 175 patients confirmed with PTB and 311 patients with NSCLC were retrospectively reviewed. Parameters including patient demographics, PET-derived morphological features and metabolic parameters, and CT-derived morphological features were investigated. Logistic regression analysis was performed to assess the independent predictive factors associated with PTB.

PTB presented with more heterogeneous glucometabolism than NSCLC in PET imaging (50% vs 17%, P < 0.05), especially in lesions with a maximum diameter < 30 mm (39% vs. 5%, P < 0.05). NSCLC usually showed centric hypometabolism, whereas PTB more frequently presented with an eccentric metabolic pattern, mainly including piebald, half-side, lesser curvature, and greater curvature shapes. Multivariate logistic regression identified that glucometabolic heterogeneity, eccentric hypometabolism, smaller lesion size, calcification, satellite lesions, and higher CT value of the hypometabolic area were independently diagnostic factors for PTB.

Morphological features derived from ¹⁸F-FDG PET images helped distinguish solitary and solid PTB from NSCLC.