Laszlo Hegedüs, Steen J. Bonnema, and Kristian H. Winther
Gilles Russ, Steen J. Bonnema, Murat Faik Erdogan, Cosimo Durante, Rose Ngu, and Laurence Leenhardt
Thyroid ultrasound (US) is a key examination for the management of thyroid nodules. Thyroid US is easily accessible, noninvasive, and cost-effective, and is a mandatory step in the workup of thyroid nodules. The main disadvantage of the method is that it is operator dependent. Thyroid US assessment of the risk of malignancy is crucial in patients with nodules, in order to select those who should have a fine needle aspiration (FNA) biopsy performed. Due to the pivotal role of thyroid US in the management of patients with nodules, the European Thyroid Association convened a panel of international experts to set up European guidelines on US risk stratification of thyroid nodules. Based on a review of the literature and on the American Association of Clinical Endocrinologists, American Thyroid Association, and Korean guidelines, the panel created the novel European Thyroid Imaging and Reporting Data System, called EU-TIRADS. This comprises a thyroid US lexicon; a standardized report; definitions of benign and low-, intermediate-, and high-risk nodules, with the estimated risks of malignancy in each category; and indications for FNA. Illustrated by numerous US images, the EU-TIRADS aims to serve physicians in their clinical practice, to enhance the interobserver reproducibility of descriptions, and to simplify communication of the results.
Kristine Z Swan, Johnson Thomas, Viveque E Nielsen, Marie Louise Jespersen, and Steen J Bonnema
Artificial intelligence algorithms could be used to risk-stratify thyroid nodules and may reduce the subjectivity of ultrasonography. One such algorithm is AIBx which has shown good performance. However, external validation is crucial prior to clinical implementation.
Materials and methods
Patients harboring thyroid nodules 1–4 cm in size, undergoing thyroid surgery from 2014 to 2016 in a single institution, were included. A histological diagnosis was obtained in all cases. Medullary thyroid cancer, metastasis from other cancers, thyroid lymphomas, and purely cystic nodules were excluded. Retrospectively, transverse ultrasound images of the nodules were analyzed by AIBx, and the results were compared with histopathology and Thyroid Imaging Reporting and Data System (TIRADS), calculated by experienced physicians.
Out of 329 patients, 257 nodules from 209 individuals met the eligibility criteria. Fifty-one nodules (20%) were malignant. AIBx had a negative predictive value (NPV) of 89.2%. Sensitivity, specificity, and positive predictive values (PPV) were 78.4, 44.2, and 25.8%, respectively. Considering both TIRADS 4 and TIRADS 5 nodules as malignant lesions resulted in an NPV of 93.0%, while PPV and specificity were only 22.4 and 19.4%, respectively. By combining AIBx with TIRADS, no malignant nodules were overlooked.
When applied to ultrasound images obtained in a different setting than used for training, AIBx had comparable NPVs to TIRADS. AIBx performed even better when combined with TIRADS, thus reducing false negative assessments. These data support the concept of AIBx for thyroid nodules, and this tool may help less experienced operators by reducing the subjectivity inherent to thyroid ultrasound interpretation.
Steen J. Bonnema, Elisabeth S. Stovgaard, Søren Fast, Kasper Broedbaek, Jon T. Andersen, Allan Weimann, Peter Grupe, Laszlo Hegedüs, and Henrik E. Poulsen
Background: Little is known about the whole body oxidative stress burden following radioactive iodine (<sup>131</sup>I) therapy of thyroid diseases. Methods: We studied 17 patients with benign nodular goiter treated with <sup>131</sup>I therapy. The targeted thyroid dose was 50 Gy in 11 patients pretreated with 0.1 mg of recombinant human TSH (rhTSH). In 6 patients, the applied thyroid dose was 100 Gy without rhTSH prestimulation. Well-established biomarkers of oxidative stress to RNA (8-oxo-7,8-dihydroguanosine; 8-oxoGuo) and DNA (8-oxo-7,8-dihydro-2'-deoxyguanosine; 8-oxodG) were measured in freshly voided morning urine (normalized against the creatinine concentration) at baseline, and 7 and 21 days after rhTSH (not followed by <sup>131</sup>I), and 7 and 21 days after <sup>131</sup>I therapy, respectively. Results: The baseline urinary excretions of 8-oxoGuo and 8-oxodG were 2.20 ± 0.84 and 1.63 ± 0.70 nmol/mmol creatinine, respectively. We found no significant changes in the excretion of any of the metabolites, neither after rhTSH stimulation alone nor after <sup>131</sup>I therapy. Also, no significant differences were found between the rhTSH group (low dose, median <sup>131</sup>I: 152 MBq) and the non-rhTSH group (high dose, median <sup>131</sup>I: 419 MBq; 8-oxoGuo: p = 0.66, 8-oxodG: p = 0.71). Conclusion: Systemic oxidative stress, as detected by nucleic acids metabolites in the urine, is not increased after thyroid stimulation with 0.1 mg of rhTSH, or after <sup>131</sup>I therapy. Our method cannot quantify the oxidative stress induced locally in the thyroid gland, but the study supports that <sup>131</sup>I therapy of benign nodular goiter carries no or only a minute risk of developing subsequent malignancies. It remains to be explored whether our findings also apply to hyperthyroid disorders.