Abstract 3302: Contribution of Cardiac F-18 FDG PET Imaging to the Management of Patients with Cardiac Sarcoidosis
Early detection and correct assessment of disease activity are critical for the optimal management of patients with cardiac sarcoidosis (CSRD). There are some recent reports showing F-18 FDG (FDG) uptake by sarcoid granulomas. In the present study, we estimated the significance of cardiac FDG PET imaging in 47 patients (57+/−11 years, 16 males and 31 females) with proven diagnosis of CSRD and receiving steroid therapy (30 – 60 mg prednisolone on alternate days) based on clinical signs of acute myocardial involvement. We interpreted regionally enhanced myocardial FDG uptake as positive in the 5-hr fasting FDG PET imaging. In addition, we determined standardized uptake value (SUV) of the FDG uptake. Before steroid therapy, positive myocardial finding was 89% (42/47) in FDG PET, 55% (21/38) in Tc-99m pyrophosphate tomographic imaging, 68% (30/44) in Ga-67 tomographic imaging, 49% (23/47) in echocardiographically estimated septal wall thinning and 35% (13/37) in biopsy. SUV was above 2.5 in all with positive FDG finding. In 3 patients with severe heart failure and with positive finding in biopsy, myocardial FDG uptake showed diffuse patterns and was hardly interpreted positive. The follow-up studies after steroid therapy revealed that the enhanced FDG uptake gradually reduced and disappeared in 6 months in most of the patients, while positive Ga-67 uptake disappeared soon after therapy. Afterwards, recurrence of active inflammation was symptomatically suspected in 4 patients. Performing FDG PET imaging, they all showed re-enhancement of myocardial FDG uptake, which contributed to decision-making of increasing steroid dose. These results suggest that the FDG PET imaging is a sensitive means in detecting disease activity of CSRD and contributes to the decision-making and evaluation of steroid therapy.