The study of plain CT combined with contrast-enhanced CT-based models for predicting malignancy of solitary solid pulmonary nodules

Abstract Background: Tocompare the diagnostic performance between only plain CT based model and plain &contrast-enhanced CT based model in the classification of malignancy for solitary solid pulmonary nodules. Methods: From January 2011 to July 2020, 527 patients with pathologically confirmed solitary solid pulmonary nodules collected at two centers with similar CT examinations and scanning parameters. Prior to surgery, all patients underwent both plain and contrast-enhanced chest CT scan. Two clinical characteristics, fifteen plain CT characteristics and four enhanced characteristics were used to develop logistic regression model with only plain CT and plain & contrast-enhanced CT. The diagnostic performance of the two models were assessed separately in the development and external validation cohorts using the AUC. Results: 392patients from A center were included in the development cohort (median size, 20.0 [IQR, 15.0-24.0] mm; mean age, 55.8 [SD, 9.9] years; male 53.3%). 153 patients from B center were included in the external validation cohort (median size, 20.0 [IQR, 16.0-24.0] mm; mean age, 56.4 [SD, 9.6] years; man 51.9%).Preoperative patients with 201 malignant (adenocarcinoma, 148 [73.6%]; squamous cell carcinoma, 35 [17.4%]; large cell carcinoma,18 [9.0%]) and 326 benign (pulmonary hamartoma, 118[36.2%]; sclerosing pneumocytoma, 35 [10.7%]; tuberculosis, 104 [31.9%]; inflammatory pseudonodule, 69 [21.2%]) solitary solid pulmonary nodules were gathered from two independent centers.. The mean sensitivity, specificity, accuracy, PPV, NPV, and AUC (95%CI) of the only plain CT based model were 0.79, 0.78, 0.79, 0.67, 0.87, and 0.88 (95%CI, 0.82-0.93), the plain & contrast enhanced CT based model were 0.88, 0.91, 0.90, 0.84, 0.93, 0.93 (95%CI, 0.88-0.98) in external validation cohort, respectively. Conclusions:A logistic regression model based on plain and contrast-enhanced CT characteristics showed exceptional performance in the evaluation of malignancy for solitary solid lung nodules. The utilization of this contrast-enhanced CT model would provide recommendations concerning follow-up or surgical intervention for preoperative patient presenting with solid lung nodules.