Thyroid Incidentalomas on 18F-FDG PET/CT: Clinical Significance and Controversies
Journal Title: Molecular Imaging and Radionuclide Therapy - Year 2017, Vol 26, Issue 3
Abstract
Objective: The purpose of the current study is to examine the incidence and clinical significance of unexpected focal uptake of 18F-fluorodeoxyglucose (18F-FDG) on positron emission tomography/computed tomography (PET/CT) in the thyroid gland of oncology patients, the maximum standardized uptake value (SUVmax) of benign and malignant thyroid incidentalomas in these patients, and review the literature. Methods: Seven thousand two hundred fifty-two 18F-FDG PET/CT studies performed over four years, were retrospectively reviewed. Studies with incidental focal 18F-FDG uptake in the thyroid gland were further analyzed. Results: Incidental focal thyroid 18F-FDG uptake was identified in 157 of 7252 patients (2.2%). Sufficient follow-up data (≥12 months) were available in 128 patients, of whom 57 (45%) had a biopsy performed and 71 had clinical follow-up. Malignancy was diagnosed in 14 of 128 patients (10.9%). There was a statistically significant difference between the median SUVmax of benign thyroid incidentalomas (SUVmax 4.8) vs malignant (SUVmax 6.3), but the wide range of overlap between the two groups yielded no clinically useful SUVmax threshold value to determine malignancy. Conclusion: 18F-FDG positive focal thyroid incidentalomas occurred in 2.2% of oncologic PET/CT scans, and were malignant in 10.9% of 128 patients. This is the lowest reported malignancy rate in a North American study to date, and significantly lower than the average malignancy rate (35%) reported in the literature. Invasive biopsy of all 18F-FDG positive thyroid incidentalomas, as recommended by some studies, is unwarranted and further research to determine optimal management is needed. There was no clinically useful SUVmax cut-off value to determine malignancy and PET/CT may not be a useful imaging modality to follow these patients conservatively. Keywords: Thyroid incidentaloma, thyroid carcinoma, 18F-fluorodeoxyglucose, 18F-FDG, positron emission tomography, PET, PET/CT
Authors and Affiliations
William Makis, Anthony Ciarallo
Keywords
Related Articles
- EP ID EP226322
- DOI 10.4274/mirt.94695
- Views 140
- Downloads 0
Risk Factors for Predicting Osteoporosis in Patients Who Receive Thyrotropin Suppressive Levothyroxine Treatment for Differentiated Thyroid Carcinoma
Objectives: Endogenous hyperthyroidism accelerates bone turnover and shortens the normal bone remodeling cycle, which results in reduced bone density. It is estimated that suppressive levothyroxine (LT4) therapy also dec...
Thyroid Incidentalomas on 18F-FDG PET/CT: Clinical Significance and Controversies
Objective: The purpose of the current study is to examine the incidence and clinical significance of unexpected focal uptake of 18F-fluorodeoxyglucose (18F-FDG) on positron emission tomography/computed tomography (PET/CT...
Cyclosporine and Vancomycin + Amikacin Induced Hot Kidney Appearance in a Young Adult and a Pediatric Patient
The appearance of a hot kidney on bone scintigraphy is rare and can be seen due to various factors. In our clinic, we observed hot kidney appearance in two patients to whom technetium-99m methylene diphosphonate (Tc-99m...
Detection of Squamous Cell Carcinoma Foci in a Patient with Dystrophic Epidermolysis Bullosa in 18F-FDG PET/CT
Dystrophic epidermolysis bullosa (DEB) is a rare, inherited skin fragility disorder characterized by blister formation in the sublamina densa. DEB is associated with aggressive squamous cell carcinoma (SCC) that has incr...
Lu-177-PSMA-617 Prostate-Specific Membrane Antigen Inhibitor Therapy in Patients with Castration-Resistant Prostate Cancer: Stability, Bio-distribution and Dosimetry
Objective: The aim of the study was to estimate the radiation-absorbed doses and to study the in vivo and in vitro stability as well as pharmacokinetic characteristics of lutetium-177 (Lu-177) prostate-specific membrane...