The Usefulness of Serial 18F-FDG PET/CT for Assessing Therapeutic Response in Cardiac Sarcoidosis with Ventricular Tachycardia

Background: The assessment of 2-deoxy-2-[18F]fluoro-D-glucose (FDG) positron emission tomography (PET)/computed tomography (CT) is a valuable diagnostic tool in the evaluation of cardiac sarcoidosis in recent years. However, the clinical value of serial quantitative 18F-FDG PET/CT to monitor the disease activity of cardiac sarcoidosis is still unknown. Case Report: We report a case of a 50-year-old woman suffered from incessant polymorphic ventricular tachycardia (VT). Continuous injection of amiodarone and landiolol reduced sustained VT and further cardiac assessment became feasible. In the first 18F-FDG PET/CT imaging showed focal cardiac uptake pattern in the septal and inferior wall of left ventricle. Gadolinium-enhanced cardiovascular magnetic resonance also showed delayed enhancement in the same cardiac segments. Immediately after these cardiac imaging, 30 mg/day of corticosteroid therapy started and the incessant polymorphic VT was successfully controlled. Daily dose of corticosteroid was gradually reduced to 10 mg and implantable cardioverter-defibrillator (ICD) implantation underwent 16 weeks after hospitalization. In the second 18F-FDG-PET/CT imaging, no 18F-FDG uptake was found in the whole ventricle. The patient has done well with no recurrence of VT and any ICD shocks during 18 months follow-up period. Conclusion: The present case indicated that serial 18F-FDG-PET/CT is feasible to determine the extent of disease activity and to quantitatively assess the response of cardiac sarcoidosis to therapy.