Cardiac Sarcoidosis: FDG PET vs. Ga-DOTANOC PET

Diagnosing cardiac sarcoidosis has always been challenging: No single imaging modality has proved effective and cardiac biopsies have a very low sensitivity. 18F-2-fluoro-2-deoxy-D-glucose fluorodeoxyglucose (FDG) PET preceded by at least 12 hours of fasting has previously been demonstrated to have reasonable accuracy, however, in some patients physiological FDG uptake in the cardiac region hampers correct identification of sarcoid granulomas. Gallium Ga 68-DOTANOC is a conjugate of the somatostatin analogue Nal3-octreotide (NOC) and gallium Ga 68-labeled 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA). We aim to study whether 68Ga-DOTANOC has superior sensitivity and accuracy than 18-FDG PET in diagnosing cardiac sarcoidosis. In addition, we aim to compare 18-FDG PET preceded by 12 hours fasting with 18-FDG PET during somatostatin blockade of insulin mediated cardiac glucose uptake.