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Background: Differentiated thyroid carcinoma (DTC) is the most common type of thyroid cancer. Treatment with surgery, radioactive iodine (RAI), and TSH suppression is effective in most patients. Five to 15% of patients become RAI refractory and need alternative therapy; however, treatment options are limited. 68 Ga-PSMA PET/CT, originally developed for prostate cancer, is also applicable to other malignancies, including thyroid carcinoma. The uptake of PSMA in thyroid carcinoma gives opportunities for imaging and therapy of RAI-refractory DTC. The aim of this study was to analyze imaging on 68 Ga-PSMA PET/CT and evaluate the response to 177 Lu-PSMA-617 therapy in patients with RAI-refractory DTC. Materials and methods: Five patients with RAI-refractory DTC underwent 68 Ga-PSMA PET/CT to determine their eligibility for 177 Lu-PSMA-617 therapy. 68 Ga-PSMA PET/CTs were analyzed visually and quantitatively. Response to 177 Lu-PSMA-617 therapy was evaluated using imaging and thyroglobulin (Tg) values. Results: Tracer uptake suspicious for distant metastases was depicted in all 68 Ga-PSMA PET/CTs. Based on tracer uptake, three patients were eligible for 177 Lu-PSMA-617 therapy, of whom two were treated. One patient showed disease progression on imaging 1 month later, while her Tg values gradually increased from 18 to 63 μg/L in the months after treatment. Another patient showed partial, temporary response of lung and liver metastases. Her Tg levels initially decreased from 17 to 9 μg/L. However, 7 months after treatment, there was disease progression on imaging and Tg levels had increased to 14 μg/L. Imaging with 68 Ga-PSMA PET/CT could be compared to 18 FDG PET/CT in three patients. Two patients showed additional lesions on 68 Ga-PSMA PET/CT, and one patient showed concordant imaging. Conclusion: 68 Ga-PSMA PET/CT appears to have added value in patients with RAI-refractory DTC, as it is able to detect various types of lesions, some of which were not picked up by 18 FDG PET/CT. Furthermore, 68 Ga-PSMA PET/ CT might be used to identify patients eligible for treatment with 177 Lu-PSMA-617. One of the two patients who underwent 177 Lu-PSMA-617 therapy showed a modest, temporary response. To draw conclusions about the effectiveness of this therapy, more research is needed.

Thyroid cancer is the most common endocrine neoplasm accounting for approximately 1,7% of total cancer diagnoses. The gold standard for evaluation of thyroid nodules is cytology from fine needle aspiration. In 30% of biopsies there is no conclusive diagnosis and patients undergo a diagnostic hemithyroidectomy. Somatic mutations occur frequently in thyroid cancer, the value of testing FNA biopsies on different mutation is analyzed, it improves accuracy, but their sensitivity is low. Another class of molecules with potential diagnostic value are miRNAs (miRNA, miR). MiRNAs function as gene regulators thereby controlling many cellular processes including cell growth, differentiation, proliferation, and apoptosis. Several studies have analyzed the expression of miRNAs in thyroid cancer, either by performing microarray analyses or validating a set of miRNAs. Recent reports focused on the diagnostic value of miRNAs in indeterminate FNA biopsies. In this systematic review we will provide an overview of all miRNAs found to be up- or downregulated in the different types of thyroid carcinomas, give an overview of the value of validated sets of microRNAs or single microRNAs in distinguishing malignant from benign lesions and conclude with a clinical view on future study strategies.

PurposeConventional thyroidectomy has been standard of care for surgical thyroid nodules. For cosmetic purposes different minimally invasive and remote-access surgical approaches have been developed. At present, the most used robotic and endoscopic thyroidectomy approaches are minimally invasive video assisted thyroidectomy (MIVAT), bilateral axillo-breast approach endoscopic thyroidectomy (BABA-ET), bilateral axillo-breast approach robotic thyroidectomy (BABA-RT), transoral endoscopic thyroidectomy via vestibular approach (TOETVA), retro-auricular endoscopic thyroidectomy (RA-ET), retro-auricular robotic thyroidectomy (RA-RT), gasless transaxillary endoscopic thyroidectomy (GTET) and robot assisted transaxillary surgery (RATS). The purpose of this systematic review was to evaluate whether minimally invasive techniques are not inferior to conventional thyroidectomy.MethodsA systematic search was conducted in Medline, Embase and Web of Science to identify original articles investigating operating time, length of hospital stay and complication rates regarding recurrent laryngeal nerve injury and hypocalcemia, of the different minimally invasive techniques.ResultsOut of 569 identified manuscripts, 98 studies met the inclusion criteria. Most studies were retrospective in nature. The results of the systematic review varied. Thirty-one articles were included in the meta-analysis. Compared to the standard of care, the meta-analysis showed no significant difference in length of hospital stay, except a longer stay after BABA-ET. No significant difference in incidence of recurrent laryngeal nerve injury and hypocalcemia was seen. As expected, operating time was significantly longer for most minimally invasive techniques.ConclusionsThis is the first comprehensive systematic review and meta-analysis comparing the eight most commonly used minimally invasive thyroid surgeries individually with standard of care. It can be concluded that minimally invasive techniques do not lead to more complications or longer hospital stay and are, therefore, not inferior to conventional thyroidectomy.

Promoter hypermethylation is a frequent event in MEN1-related and sporadic PanNETs. Targeting DNA methylation could be of therapeutic value in MEN1 patients with advanced PanNETs.