Evaluation of the 18F-PSMA Positron Emission Tomography (PET)/CT in Patients With Medullary Thyroid Cancer (MIMETIC)

Evaluation of the 18F-PSMA Positron Emission Tomography (PET)/CT in Patients With Medullary Thyroid Cancer

Prospective, Single-centre, Feasibility Study to Evaluate the Use of 18F-PSMA PET/CT in Patients With Biochemically Active Medullary Thyroid Cancer

Rationale: In patients with medullary thyroid cancer (MTC), molecular imaging is used to assess the extent of disease in the primary diagnostic process and follow-up period to determine possible therapeutic options. The currently most used tracer in clinical practice, F-18 labelled fluorodeoxyglucose (18F-FDG), does not accurately detect MTC tumors with an indolent growth rate. A new, complimentary tracer is warranted to detect different subtypes. Objective: The primary objective is to assess the feasibility of using the F-18 labelled prostate specific membrane antigen (18F-PSMA) PET/CT for (re)staging patients with medullary thyroid cancer. The secondary objective is to compare the ability to detect MTC with the 18F-PSMA PET/CT to that of the 18F-FDG PET/CT. Study design: Prospective, single-centre, feasibility study. Study population: Patients (18 years of age or older) with biochemically and cytological/histological confirmed MTC, for whom the indication of an 18F-FDG PET/CT for tumor staging has already been determined on clinical grounds. Main study parameters/endpoints: The primary outcome of this study is the performance (lesion-based//patient-based sensitivity) of the 18F-PSMA PET to detect MTC lesions in patients with cytologically/histologically confirmed disease. Secondarily, the performance of the 18F-PSMA PET will be compared to the 18F-FDG PET/CT.

Medullary Thyroid Cancer, Medullary Thyroid Carcinoma, Thyroid Carcinoma, Medullary, Thyroid Cancer, Medullary

PSMA PET/CT, 18F-PSMA PET/CT, Fluorine-18 Labeled Prostate Specific Membrane Antigen, Prostate Specific Membrane Antigen, Thyroid Cancer, Medullary Thyroid Cancer, Medullary Thyroid Carcinoma

Only 1 arm exists in this study. Patients with Medullary Thyroid Cancer undergo a PET/CT after receiving the Fluorine-18 labeled prostate specific membrane antigen (18F-PSMA-1007) tracer intravenously. Each patient will undergo this process one time. Patients will receive 3 MBq/kg (+- 10%) in 8,3 ml (maximum 400 MBq). Waiting time after injection is 60 minutes. Scanning time is approximately 45 minutes.

Comparison of patient- and lesion-based sensitivity. Comparison of Standardized Uptake Values (SUVs).

Correlation between 18F-PSMA uptake in tumor lesions and serum carcinoembryonic antigen (CEA) values.

Inclusion Criteria: 18 years of age or older Histological or cytological proven MTC Biochemical evidence of disease activity (elevated/increasing calcitonin and/or CEA) Clinical indication for an 18F-FDG PET/CT Able to follow instructions to participate in the study Able to give informed consent Exclusion Criteria: Patients with prostate cancer or renal cell carcinoma Pregnant patients Recent neck surgery (<3 months ago)