The use of 18F-FDG PET/CT may be a helpful additional investigation as it has high diagnostic accuracy for the detection of recurrent and/or metastatic diseases in DTC patients with thyroglobulin elevation and negative iodine scintigraphy (Larg et al. 2019, Qichang et al. 2019, Wang et al. 2021). This evidence concerns the gene TG and metastatic neoplasm.