Development and validation of a CT-based nomogram for predicting invasiveness in solitary pulmonary ground-glass nodules.

This study aimed to develop and validate a nomogram based on clinical and computed tomography (CT) features for the preoperative prediction of invasiveness in patients with solitary pulmonary ground-glass nodules (GGNs). We retrospectively analyzed 846 patients with solitary GGNs who underwent surgical resection at the Lung Cancer Center of West China Hospital between November 2022 and January 2024. All nodules were pathologically confirmed as atypical adenomatous hyperplasia (AAH), adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), or invasive adenocarcinoma (IAC). Patients were classified into a non-invasive group (including AAH, AIS, and MIA) and an IAC group based on postoperative pathological results. Clinical data and CT features before surgery were collected. Patients were randomly assigned to a training cohort (n = 592) and a validation cohort (n = 254) in a ratio of 7:3. Least absolute shrinkage and selection operator (LASSO) regression was used for feature selection, followed by multivariate logistic regression to identify independent predictors and construct a nomogram model. The variance inflation factor (VIF) was used to evaluate multicollinearity among the candidate predictors. Model performance was assessed using the area under the receiver operating characteristic curve (AUC), calibration curves, and decision curve analysis (DCA). Multivariate logistic regression analysis revealed that the maximum tumor diameter (OR = 39.82, 95% CI: 16.29-97.32), consolidation-to-tumor ratio (0.5<CTR<1, OR = 2.51, 95% CI: 1.36-4.63), vacuole sign (OR = 2.29, 95% CI: 1.29-4.07), pleura traction sign (OR = 3.03, 95% CI: 1.66-5.53), and the presence of solid component on the mediastinal window (OR = 3.27, 95% CI: 1.46-7.28) were independent risk factors for IAC. The nomogram constructed based on these variables demonstrated good discriminative ability, with AUC values of 0.930 and 0.913 in the training and validation cohorts, respectively. Calibration curves demonstrated good agreement between the predicted and observed probabilities, and DCA indicated favorable clinical utility. Consequently, this nomogram based on the maximum tumor diameter, CTR, vacuole sign, pleura traction sign, and the presence of solid component on the mediastinal window, provides an effective and noninvasive tool for preoperative prediction of the invasiveness of solitary GGNs.