Ultra-High-Resolution CT Features of Pulmonary Nodules Correlate with Visceral Pleural Invasion in Early Stage Lung Adenocarcinoma

Abstract

Backgroundvisceral pleural invasion (VPI) is an important prognostic factor in early stage lung adenocarcinoma, which can affect the TNM Classification of Tumors.PurposeTo investigate whether ultra-high-resolution computed tomography (U-HRCT) features can predict VPI of early stage pulmonary nodules contacting the interlobar pleura.Material and MethodsA total of 126 patients with lung adenocarcinoma (age, 24-77 years) confirmed by surgical pathology were retrospectively enrolled. All patients underwent U-HRCT scan and were divided into two groups according to pulmonary nodular type: pure (pGGN) and mixed (mGGN). Clinical features were recorded, and U-HRCT features were manually measured using PHILIPS EBW V4.5.5. Univariate and multivariate logistic regression were used to determine factors that can significantly predict VPI. ResultsU-HRCT and three-dimensional orthogonal post-processing method could better display the relationship between GGNs and interlobar fissures. Among all patients, fifteen patients (12%) had VPI. None of the patients with pGGN had VPI. In the mGGN group, the solid ratio (odds ratio [OR]=1.275, 95% CI 1.1-1.478; P=0.001) and solid diameter (OR=1.139, 95% CI 1.06-2.346; P=0.046) were independent risk factors for VPI in early stage lung adenocarcinoma. For VPI diagnosis, the area under the curve, sensitivity, and specificity of the solid ratio and solid diameter were 0.803, 80%, and 75% and 0.807, 80%, and 80.36%, respectively.ConclusionU-HRCT can display GGNs and interlobar fissures in detail. VPI was not detected in patients with pGGN. In patients with mGGNs, a solid diameter >6mm and solid ratio >38% can be independent predictors of VPI, which may be helpful in surgical decision-making.