Endocrine Abstracts (2011) 26 P468

A diagnostic value of elastosonographically determined strain index in the differential diagnosis of benign and malignant thyroid nodules

Bekir Cakir, Cevdet Aydin, Birol Korukluoglu, Didem Ozdemir, Cagatay I Sisman, Dilek Tuzun, Ayten Oguz, Gulnur Guler, Guven Guney, Ahmet Kusdemir, Yavuz S Sanisoglu & Reyhan Ersoy

Ataturk Education and Research Hospital, Bilkent, Ankara, Turkey.

Aim: In this study, we aimed to determine the strain index (SI) as well as the ES scoring of thyroid nodules, and establish the role for these parameters in the differential diagnosis of thyroid nodules using histopathological analysis as a reference standart.

Materials and method: Real-time ES in transverse axis (TA) and longitudinal exis (LA) was performed in 391 nodules of 292 patients. ES scoring was made for all the nodules. SI in TA and LA was calculated for 4 times in each nodule and mean values were determined. The results were compared with final histopathological diagnosis.

Results: In histopathological examination, 125 (31.97%) of 391 nodules were malignant and 266 (68.03%) were benign. Of these histopathologically benign nodules, 189 (%71.05) were also in probably benign group according to elastosonographic scoring (score 1,2,3), while 77 (28.95%) were in probably malignant group (score 4,5). Among 125 histopathologically malignant nodules, 52 (41.60%) were in probably benign and 73 (58.40%) in probably malignant group according to elastosonographic scoring. There was a significant relation between scoring and histopathological findings (χ2=36.513; P<0.001). Accordingly, sensitivity and specifity of ES scoring were 58.4 and 71.0%, respectively. ROC analysis value obtained for strain ratios in LA (AUC: 75.5%; P<0.001) had a higher significance compared to ROC analysis value obtained for strain ratios in TA (AUC:66.0%). Thus, ROC analysis evaluation was applied only for SI in LA. The optimal SI cut-off value in LA for all the nodules was found to be 16.709 (sensitivity: 73.4%, specifity:70.0%) (AUC: 75.4±0.03%; 70.2–80.5%). SI cut-off value corresponding to 90% sensitivity in this axis was 4.516 (specifity: 35.7%).

Conclusion: This study indicates that measurement of SI with ES as a non-invasive procedure may be used as an adjunctive method to the conventional methods for the differential diagnosis of thyroid nodules.