Aim: We aimed to determine strain index (SI) values using Elastosonography (ES) in histopathologically confirmed differentiated thyroid carcinomas (DTC) and investigate the role of these values for the differential diagnosis of nodular thyroid diseases.
Material and method: ES in longitudinal axis (LA) was performed in 391 thyroid nodules of 292 patients. ES scores of thyroid nodules were determined and SI in LA for each nodule was calculated. The findings were compared with histopathological results.
Results: Histopathologically, of 391 nodules, 125 (31.97%) were malignant and 266 (68.03%) were benign. Among 125 malignant nodules, 100 were papillary thyroid carcinoma (PTC) (70 classical, 24 follicular variant, 3 solid trabecular variant, 2 columnar variant, 1 oncocytic variant), 15 were follicular carcinoma, 9 were hurthle cell carcinoma and 1 was medullary carcinoma. When we compared SI of 100 nodules with PTC/PTC variants and 266 benign nodules, we found that SI cut-off value for 90% sensitivity (Sn) was 5.885 (AUC 77.6±0.03%; P=0.014). In hypoechogenic nodules with ES score of 45, irregular margins and type 1 vascularization pattern, SI cut-off value for 90% Sn was 17.020 (Sp: 50%, AUC 72.4±0.08%; P=0.011). Data of 70 nodules with classical PTC was compared with data of benign nodules and SI cut-off value for 90% Sn was calculated as 7.885 (AUC 79.2±0.03%; P<0.001). The optimal SI cut-off value in 30 nodules with variant PTC was 14.785 (Sn:73.3%, sp:66.2%, PPV:19.6%, NPV:95.7%). In these nodules, SI cut-off value for 90% Sn in LA was 4.480 (Sp:35.7). Since sample sizes of follicular and hurthle cell carcinomas were small, we did not make any analysis for these nodules.
Conclusion: SI measurement using ES may be a valuable method with high sensitivity in PTC and PTC variants, however further studies with larger sample sizes are required to conclude about follicular and hurthle cell carcinomas.
30 Apr - 04 May 2011
European Society of Endocrinology