Diagnostic value of FDG PET/CT imaging.

Area of Science:

• Nuclear Medicine
• Oncology
• Radiology

Background:

• Differentiated thyroid cancer (DTC) has a good prognosis, but local recurrences and distant metastases occur in 20% and 10% of patients, respectively.
• Existing prognostic systems struggle to predict outcomes for patients with late-stage metastases.
• 18-F-fluoro-deoxyglucose (FDG) positron emission tomography (PET) and PET/CT have emerged as valuable tools in DTC evaluation.

Purpose of the Study:

• To review and summarize published data on the utility of FDG-PET/CT in differentiated thyroid cancer (DTC).
• To identify the optimal indications for FDG-PET/CT in DTC follow-up and staging.
• To explore the prognostic value of FDG imaging in DTC recurrence.

Main Methods:

• Systematic review of literature on FDG-PET/CT use in DTC.
• Analysis of FDG-PET/CT accuracy in relation to thyroglobulin (Tg) levels and thyroid-stimulating hormone (TSH) stimulation.
• Evaluation of FDG imaging for prognostic stratification of DTC patients.

Main Results:

• FDG-PET/CT is highly accurate for evaluating DTC patients with elevated thyroglobulin levels and negative radioiodine scans, often leading to changes in patient management.
• A strong correlation exists between FDG-PET/CT accuracy and thyroglobulin levels, with enhanced performance under TSH-stimulated conditions.
• FDG imaging provides insights into tumor biology and aids in prognostically stratifying DTC patients with recurrences.

Conclusions:

• FDG-PET/CT is indicated for DTC follow-up in cases of high thyroglobulin levels with negative radioiodine scans.
• FDG-PET/CT is not routinely recommended for initial staging of DTC or for evaluating indeterminate thyroid nodules.
• FDG imaging offers significant value in assessing DTC recurrence and guiding treatment decisions.