Whole Body FDG PET-CT in the Evaluation and Management of Cardiac Sarcoidosis and Isolated Cardiac Sarcoidosis

Abstract

Introduction Sarcoidosis is a multisystem inflammatory disease defined histologically by the formation of non-caseating granulomas. Cardiac involvement can be seen in up to 5% of cases [1]. These patients are at a high risk for major cardiac events [1]. Diagnosing and monitoring Cardiac Sarcoidosis (CS) is not trivial but can be currently accomplished by a combination of cardiac MRI and cardiac FDG PET-CT scanning [2]. With appropriate patient preparation, cardiac FDG PET has a high sensitivity for detecting cardiac lesions but also extra-cardiac lesions and for monitoring the efficacy of treatment. Discussion Current standard clinical practice consists of acquiring dedicated, limited field of view cardiac FDG PET scans. This would cover the heart and immediately adjacent thoracic structures. Although this is of great value and used with great success to diagnose and monitor cardiac sarcoidosis, it fails to assess the patient’s disease in a holistic manner. Still with this limited field of view, several reports including ours have described a high rate of extra-cardiac findings. We reviewed a series of sixty-five PET-CT scans of 54 patients referred for CS evaluation. These were performed between September 2010 and April 2013 at Yale New Haven Hospital and we found extra-cardiac findings were present in 92.3% of scans (n=60). Overall disease distribution is summarized in (Table 1). Highlight some of these extra-cardiac findings (Figures 1-4). 52.3% of these patients were asymptomatic at the time of the scan. CS was diagnosed in 50.8% of patients (n=33). All the patients (100%) with CS had extra-cardiac findings. Additionally, extra-cardiac findings were present in 48.3% of the scans when there was no cardiac involvement. In our cohort, we had no cases of Isolated Cardiac Sarcoidosis (ICS).