ACTA ENDOCRINOLOGICA (BUC)

Context. Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer due to its high fibrotic content; it can affect the blood flow resistance. Objective. To introduce duplex Doppler ultrasonography (DDUS) parameters of papillary thyroid carcinoma (PTC) and their correlation with size. Design. The study was designed as a prospective study. Subjects and Methods. Thyroid nodules of the patients who were already scheduled for thyroid surgery either for malignant thyroid nodules or multinodular goiter were evaluated for DDUS parameters. Size, systolic to diastolic flow velocity (S/D) ratio, pulsatility index (PI), and resistive index (RI) of each nodule were recorded. Nodules were diagnosed as PTC or benign nodules based on histopathology. DDUS parameters were compared between PTCs versus benign nodules and micro PTCs (≤ 10 mm) versus large PTCs (> 10 mm). A correlation analysis was performed between the size and DDUS parameters. Results. 140 thyroid nodules (30 PTCs, 110 benign nodules) were obtained. The mean S/D ratio, PI, and RI values were significantly higher in PTC than in benign nodules (p values were 0.0001, 0.0003, and 0.0001 respectively). The optimal cut-off values of S/D (0.732), PI (0.732), and RI (0.738) had accuracy rates of 71%, 69%, and 69%, respectively. There was no statistically significant difference between micro PTC and large PTC with regards to DDUS parameters. The size and DDUS parameters of PTC showed no significant correlation. Conclusions. PTC has a high resistive flow pattern regardless of its size; however the clinical utility of DDUS to differentiate a PTC from benign nodule is limited.