Qualitative and Quantitative Computed Tomography Analyses of Lung Adenocarcinoma for Predicting Spread Through Air Spaces.

Background/objectives: Spread through air spaces (STAS) is defined as the spread of tumor cells into the parenchymal alveolar space beyond the margins of the main tumor, and it is associated with worse clinical outcomes in resected lung adenocarcinoma. This study aimed to evaluate the preoperative computed tomography (CT) findings of primary lung adenocarcinoma in surgically resected T1 cases and to compare CT findings with and without STAS.

Methods: A total of 145 patients were included in this study. The following factors were evaluated on CT images: nodule type (pure ground-glass nodule [GGN], part-solid nodule, or solid nodule), margin (smooth or irregular), the presence of lobulation, spicula, cavity, calcification, central low attenuation, peripheral opacity (well-defined or ill-defined), air bronchogram, satellite lesions, pleural retraction, pulmonary emphysema, and interstitial pneumonia; CT values (maximum, minimum, and mean); volume (tumor and solid component); and diameter (tumor and solid component). CT criteria were compared between the presence and absence of STAS.

Results: Lobulation and central low attenuation were significantly more frequent in patients with STAS (p < 0.05). The mean CT value, and the volume, rate, and diameter of the solid component were significantly larger in cases with STAS (p < 0.05). A multiple logistic regression analysis identified central low attenuation as an indicator of the presence of STAS (p < 0.001; odds ratio, 3.993; 95% confidence interval, 1.993-8.001).

Conclusions: Quantitative and qualitative analyses are useful for differentiating between the presence and absence of STAS.