@article{Grmek_Jamšek_Žagar_Gaberšček_2015, title={Thyroid lesion incidentally detected by 18F-FDG PET-CT – a two centre retrospective study}, volume={49}, url={https://www.radioloncol.com/index.php/ro/article/view/2195}, abstractNote={<p><strong>Background.</strong> Thyroid PET incidentalomas represent a diagnostic challenge. The SUV<sub>max</sub> value is one possible parameter that can help in distinguishing between benign and malignant thyroid PET lesions.</p> <p><strong> </strong></p> <p><strong>Materials and methods.</strong> We retrospectively evaluated 5911 <sup>18</sup>F-FDG PET-CT examinations performed at two different medical centres from 2010 to 2011. If pathologically increased activity was accidentally detected in the thyroid (incidentaloma), the SUV<sub>max</sub> value of the thyroid lesion was calculated. Patients with incidentalomas were instructed to visit a thyroidologist, who performed further investigation including fine needle aspiration cytology (FNAC) if needed. Lesions deemed suspicious after FNAC were referred for surgery.</p> <p><strong> </strong></p> <p><strong>Results.</strong> In the first centre the incidence of thyroid incidentalomas was 2.89%. In 5 of 41 patients with focal incidentaloma a malignant lesion was detected. The SUV<sub>max</sub> value of benign lesions was 5.6 ± 2.8 and for malignant 15.8 ± 9.2 (<em>p</em> < 0.001). In the second centre the incidence of thyroid incidentalomas was 4.82%. Benign lesions were detected in 20 patients and malignant in 5 patients. The SUV<sub>max</sub> value of benign lesions was 3.7 ± 2.2 and 5.1 ± 2.3 for malignant lesions (<em>p</em> = 0.217).</p> <p>All 29 further investigated diffuse thyroid PET incidentalomas were benign.</p> <p><strong> </strong></p> <p><strong>Conclusions.</strong> Thyroid PET incidentalomas were found on <sup>18</sup>F-FDG PET-CT examinations in 2.89% and 4.82% respectively. Only focal thyroid PET incidentalomas represented malignant lesion in 12% (first centre) and in 20% (second centre). The SUV<sub>max</sub> value may help in distinguishing between benign and malignant thyroid PET lesions, but it must be used with caution.</p>}, number={2}, journal={Radiology and Oncology}, author={Grmek, Marko and Jamšek, Jan and Žagar, Ivana and Gaberšček, Simona}, year={2015}, month={Apr.} }