Establishment of clinical predictive model of malignant probability of solitary pulmonary nodules

ObjectiveTo screen the independent risk factors for malignant solitary pulmonary nodules, and build a nomogram model to estimate the probability of malignancy.

MethodsThe clinical data and chest imaging characteristics of patients with solitary pulmonary nodules who underwent surgical treatment and had definite pathology in the Department of Thoracic Surgery were collected.The independent risk factors were screened by univariate and multivariate logistic regression analysis, and a nomogram mathematical model was established to predict the malignant probability of solitary pulmonary nodules.Finally, the risk prediction model was validated using the area under the curve (AUC) of receiver operating characteristic (ROC) and the calibration curve.

ResultsAmong 605 patients, there had 398 (65.8%) cases of malignant lesions, and 207 benign lesions.In multivariate analysis, patient's age, lampblack, ground-glass opacity, long-spiculation, short- spiculation, pleural indentation, vessel convergence, vacuole sign, calcification and deep-lobulation were independent influencing factors of malignant solitary pulmonary nodules (P < 0.05 to P < 0.01).The above independent influencing factors were included in the nomogram to construct a mathematical model to predict the malignant probability of solitary pulmonary nodules.The nomogram model showed better discrimination and consistency.The AUC was 0.913 (95%CI: 0.888-0.938).When T=0.55 was intercepted, the Youden index was the largest, with a sensitivity of 89.2% and a specificity of 80.2%.The calibration curve showed that the predicted malignancy probability of solitary pulmonary nodules was substantially parallel to the probability of actual malignant tumors, with a slope of approximately 45°.Calibration graphic revealed adequate fit of the model predicting the risk of malignancy probability of solitary pulmonary nodules.

ConclusionsAge, lampblack, ground-glass opacity, short-spiculation, pleural indentation, vessel convergence, vacuole sign, and deep-lobulation are independent risk factors for malignant solitary pulmonary nodules, while calcification and long-spiculation are more common in benign solitary pulmonary nodules.A new nomogram model, allowing clinicians to individualize, visualize and accurately predict the malignant probability of solitary pulmonary nodules.