Nomogram for the diagnosis of suspected papillary thyroid carcinomas based on sonographic patterns: a retrospective study.

Abstract

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. 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. 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). Our novel nomogram risk score model based on the US features accurately predicted PTC nodule diagnosis.