18F-FDG PET-CT in the clinical management of cardiac sarcoidosis: A regional academic referral center experience.

1527 Objectives: To evaluate the role of 18F-FDG PET-CT in the clinical management of cardiac sarcoidosis (CS), including its initial diagnosis and assessment following therapy. Method and Materials A retrospective review of 168 consecutive patients who received 18F-FDG PET-CT for suspected CS was performed. Data regarding patient demographics, scan findings, and administered therapies (prednisone, methotrexate, or dual therapy) was collected and analyzed. Follow-up 18F-FDG PET-CT scans were compared with the initial scans obtained at diagnosis, and assessed for changes. All 18F-FDG PET-CT scans were performed using a standard protocol as recommended by Society of Nuclear Medicine guidelines. Results A total of 62/168 (37%) of the patients undergoing 18F-FDG PET-CT for the initial diagnosis of CS had evidence of cardiac involvement. A total of 36/168 (21%) of the patients received at least one follow-up study (16 from the group initially positive for CS and 20 patients from the group initially negative for CS). Of the 16 patients with positive studies at initial diagnosis, 7 (44%) patients showed resolution of disease (mean follow-up time 687±232 days), whereas 9 (56%) patients showed persistent disease (mean follow-up time 260±57 days, p=0.39). A total of 2/7 (29%) patients who showed resolution of disease were on dual prednisone and methotrexate therapy. No patients in the group with persistent disease were on dual immunomodulator therapy. Conclusion18F-FDG PET-CT is an effective tool in the clinical management of CS, including its initial diagnosis and assessment following therapy. Although not statistically significant, patients treated for a longer duration were more likely to respond to the therapy. Additionally, dual immunomodulator therapy with prednisone and methotrexate may improve therapeutic response in CS. Figure 1. F-18 FDG PET-CT MIP and axial fused PET-CT images showing (A) focal on diffuse hypermetabolic activity in the left ventricular myocardium consistent with cardiac sarcoidosis, and (B) resolution of the myocardial activity following immunomodulator therapy. It is important to note the scans also revealed persistent pulmonary, as well as mediastinal and hilar nodal involvement.