Thyroid Follicular Carcinoma with Iodine-Avid Bone Metastases Showing Mild Uptake on Both 18F-FDG and 68Ga-DOTATOC PET/CT
Differentiated thyroid carcinoma (DTC) is usually characterized by good prognosis. Radioiodine scan is the first-line diagnostic tool to detect the metastatic disease. In patients with high Tg levels suggesting metastatic disease when radioiodine scan is negative, 18F-fluorodeoxyglucose positron emission tomography/computerized tomography (FDG PET/CT) is reported to be effective in defining the metastatic foci. Another imaging modality is somatostatin receptor imaging with PET/CT which can be used especially when 18F-FDG PET/CT is nondiagnostic. Peptide receptor radionuclide therapy with β-emitting radionuclides may be considered when somatostatin positivity is defined in metastatic lesions. In this case report, a patient with DTC having radioiodine-positive bone metastases showing mild uptake in 18F-FDG PET/CT and 68Ga-DOTATOC PET/CT is presented.
KeywordsDifferentiated thyroid carcinoma Bone metastasis Radioiodine 18F-FDG PET/CT Somatostatin receptor imaging
- 2.Nagamachi S, Wakamatsu H, Kiyohara S, Nishii R, Mizutani Y, Fujita S, et al. Comparison of diagnostic and prognostic capabilities of 18F-FDG-PET/CT, 131I-scintigraphy, and diffusion-weighted magnetic resonance imaging for postoperative thyroid cancer. Jpn J Radiol. 2011;29:413–22.CrossRefGoogle Scholar
- 9.Jois B, Asopa R, Basu S. Somatostatin receptor imaging in non-(131)I-avid metastatic differentiated thyroid carcinoma for determining the feasibility of peptide receptor radionuclide therapy with (177)Lu-DOTATATE: low fraction of patients suitable for peptide receptor radionuclide therapy and evidence of chromogranin a level-positive neuroendocrine differentiation. Clin Nucl Med. 2014;3:505–10.CrossRefGoogle Scholar