Purpose Ultrasound elastography (USE) is a newly developed technique for the evaluation of tissue stiffness. It is known that malignancies often show a low-strain value. So far, only limited data for thyroid nodules is available. Methods This study included 309 prospective evaluated patients with dominant, nontoxic thyroid nodules. All patients were referred to surgery. USE was performed preoperatively. Three measuring groups were formed: hard (< 0.15), intermediate (0.16-0.3), and soft (> 0.31). The measurements were correlated to the final histological findings. Results The strain rated from 0.01 to 0.84 (mean 0.26±0.13). A total of 50 thyroid malignancies (35 papillara carcinoma, 9 medullary carcinoma, and 6 follicular carcinoma) were observed. Patients (81) were within the hard group, 35 of them (43.2%) had thyroid cancer (TC) in final histology. Out of 132 patients in the intermediate group, 15 patients had TC (11.4%). All 96 patients from the soft group showed benign histological results (NPV 100%). Seventy percent of patients with TC were within the hard group (PPV 42%). These results were highly significant (p<0.001). Coarse calcifications and cystic nodules were not connected with reliable measurements and therefore are not suitable for USE. Conclusion USE is a useful adjunctive tool in the workup of thyroid nodules. A low strain value needs surgical intervention, whereas a high strain value predicts a benign histology. It might substitute fine-needle aspiration cytology in the future.

The operative therapy of the autonomous thyroid deals almost exclusively with nodular goiters. There are only rare situations with purely diffuse autonomy in surgical patients. The endpoint of operative therapy is permanent elimination of clinically relevant autonomous function and thereby irreversible abolition of thyrotoxicosis, even in their latent form. Clinically relevant autonomous function normally ist linked to nodular structures of different size and different distribution, so that this aim corresponds automatically with the aim of complete removal of nodular structures, both in autonomous and in non-autonomous goiters. Function is best preserved by leaving a homogenous remnant of considerable size. In different particular clinical situations (for example pregnancy, suspicion of malignancy, recurrent goiter, intrathoracic goiter, thyrotoxic crisis, Marine-Lenhart-syndrome) the basic principal of operative strategy is varied according to the respective situations. Unsatisfactory operative results are mainly caused by incomplete removal of nodules, based on insufficient surgical performance of morphological and functional diagnostics, which is related to operative uniformity. An operative strategy, which ist "fitted to morphology" and "regarding function" and which we call "selective strategy", in our opinion ist highly appropriate, to avoid remnant nodules and remnant autonomy and to preserve an normal remnant, even in different position and of different size. This selective surgery ist applicable both to autonomous and non-autonomous goiter. Compared with the classic subtotal, uniform procedure the incidence of remnant nodules is reduced from about 50% to about 5 %. Remnant autonomy is almost excluded, when mistakes are avoided (about 1%). The incidence of recurrent goiter and recurrent thyrotoxicosis is lowered to under 5%--but up to now there are too few reliable long-term follow-up studies. The selective surgery strategy demands flexibility regarding operative tactics, which can be simply classified into 5 basic situations, which we relate to the operative procedure per thyroid lobe. It requires experience and competence in carefully dissecting and--when necessary--manipulating the recurrent laryngeal nerve und the parathyroid glands. Under these conditions it is followed by a comparatively low rate of complications (permanent recurrent laryngeal nerve paralysis and hypoparathyroidism under 1%, respectively). Thus, the old dilemma of thyroid surgery can be solved, which consists of radical operation with higher morbidity and lower frequency of recurrent disease on the one hand and more limited operative procedures with fewer complications but more frequent recurrencies on the other hand.

With IOPUS, more nodules are detectable, size and structure of the remnants are optimized, and the number of nodular lesions in thyroid remnants is lower. Thus, an even lower risk of recurrence can be expected for long-term follow-up. All in all, the routine use of IOPUS can be advocated, with maintenance of the selective operative strategy.

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