A new observational study aims to assess the feasibility of using F-18 labeled prostate-specific membrane antigen (18F-PSMA) as a tracer for positron emission tomography/computer tomography (PET/CT) imaging for the staging of medullary thyroid carcinoma (MTC).

The study will also compare 18F-PSMA to the most commonly used tracer in clinical practice, F-18 labeled fluorodeoxyglucose (18F-FDG), to see which is better at detecting MTC on PET/CT imaging.

Molecular imaging is typically used to determine the extent of MTC during the primary diagnostic process and follow-up period to guide treatment strategies.

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According to the study’s sponsor, the University Medical Center Groningen in the Netherlands, “The currently most used tracer in clinical practice, F-18 labeled fluorodeoxyglucose (18F-FDG), does not accurately detect MTC tumors with an indolent growth rate. A new, complimentary tracer is warranted to detect different subtypes.”

Read more about MTC testing.

The prospective, single-center, feasibility study aims to recruit 15 patients with histologically or cytologically proven MTC. Participants must be 18 years of age or older, have biochemical evidence of disease activity such as elevated or increasing levels of calcitonin and/or carcinoembryonic antigen (CEA), and have a clinical indication for an 18F-FDG PET/CT.

During the study, each patient will undergo a single session of PET/CT imaging after receiving an intravenous infusion of 18F-PSMA-1007 tracer at a dose of 3 MBq/kg in 8.3 mL (up to a maximum of 400 MBq). Scanning will take about 45 minutes after a 60-minute wait time following the infusion.

The primary endpoint for the study is the sensitivity of 18F-PSMA for the detection of MTC. The comparison of 18F-PSMA with 18F-FDG is a secondary outcome of the study. Other secondary outcomes include comparisons of 18F-PSMA uptake in tumor lesions with serum calcitonin levels and CEA values. 18F-FDG uptake in tumor lesions will also be compared with serum calcitonin and CEA levels.

Researchers aim to begin recruitment soon at the university. The estimated primary completion date of the study is September 2024 with an estimated study completion date being December 2024.


Evaluation of the 18F-PSMA positron emission tomography (PET)/CT in patients with medullary thyroid cancer (MIMETIC). ClinicalTrials.gov. September 9, 2022. Accessed September 22, 2022.