Efficacy of color Doppler ultrasound signs combined with serum tumor-specific growth factor in the diagnosis of differentiated thyroid cancer

Objective: To construct a diagnostic model for follicular thyroid carcinoma (FTC) and papillary thyroid carcinoma (PTC), both subtypes of differentiated thyroid carcinoma (DTC), using color Doppler ultrasound signs in conjunction with serum laboratory markers. Methods: We conducted a retrospective analysis of patients with thyroid nodules who underwent ultrasonography at Yulin Hospital from February 2021 to March 2023. The cohort included 269 subjects: 105 with benign nodules and 164 with DTC (59 with FTC and 105 with PTC). We compared baseline demographics and laboratory indices between the groups. Diagnostic values of ultrasound features and laboratory markers were assessed using receiver operating characteristic (ROC) curves, and logistic regression was employed to pinpoint independent diagnostic factors for FTC. A predictive nomogram was subsequently developed based on these factors. Results: There were significant differences between the benign and malignant groups regarding ultrasound signs (including border, morphology, echogenicity, calcification, blood flow, lymph node zoning) and laboratory indices (free triiodothyronine (FT3), free thyroxine (FT4), thyroglobulin (Tg), thyroid-stimulating hormone (TSH), vascular endothelial growth factor (VEGF), tumor-specific growth factor (TSGF)), with all P-values <0.05. The areas under the curve (AUCs) for FT3, FT4, Tg, TSH, VEGF, and TSGF were all above 0.75, with Tg achieving the highest at 0.91. Logistic regression identified borders, morphology, echogenicity, VEGF, and TSGF as independent diagnostic factors for distinguishing between FTC and PTC, with significant P-values. The constructed nomogram demonstrated an AUC of 0.853, indicating high diagnostic accuracy. Both calibration and decision curve analysis (DCA) validated the model's stability and clinical utility. Conclusion: We successfully developed a nomogram combining ultrasound features and serum markers that enhances the diagnostic precision for FTC. This model offers a valuable tool for clinical diagnostics in differentiated thyroid cancer.