Background: High resolution ultrasonography (US) is the first choice for diagnosis of thyroid cancer and is based on many sonographic features: composition, echogenicity, margins, calcifications, shape and vascularity. Here, we tried to develop a nomogram to evaluate papillary thyroid carcinoma (PTC) based on sonographic features.
Methods: From Aug 2016 to Dec 2017, a primary cohort of 382 patients with suspicious thyroid nodules and accepted US examinations were included in Gansu Provincial Hospital. Sonographic features were used to develop a nomogram with Cox regression analysis. The nomogram was validated using prospective data from 162 patients as the validation group.
Results: The primary and validation cohort showed comparable clinical and US features in all aspects. Univariate and multivariate analyses showed solid composition [odds ratio (OR): 3.785; 95% confidence interval (CI): 1.504-9.528, P=0.005], hypoechoic (OR: 15.840; 95% CI: 5.754-43.602, P<0.001) and irregular margins (OR: 15.953; 95% CI: 5.897-43.160, P<0.001), microcalcifications (OR: 21.730; 95% CI: 7.119-66.329, P<0.001), taller than wide shape (OR: 5.153; 95% CI: 1.997-13.311, P=0.001), internal high vascularization (OR: 6.288; 95% CI: 2.175-18.181, P=0.001), and obscure borders (OR: 5.648; 95% CI: 2.118-15.065, P=0.001) as risk factors for PTC. Based on the seven risk factors, nomogram was developed and validated by a prospective group, and discrimination and calibration were measured using the concordance index (C-index).
Conclusions: Our novel nomogram risk score model based on the US features accurately predicted PTC nodule diagnosis.
Keywords: Papillary thyroid carcinoma (PTC); nomogram; ultrasonography (US).