PO89 - Enhanced Myocardial Suppression on ¹⁸F-FDG PET/CT in Suspected Cardiac Sarcoidosis with an 18-Hour Fasting Protocol
HY Santema (Netherlands)1; D Vriens (Netherlands)2; FAJ Esser (Netherlands)3; HMJ Siebelink (Netherlands)4; JL Stöger (Netherlands)5; JJ Goeman (Netherlands)6; JRG Torremans (Netherlands)1; MM Tjong Joe Wai (Netherlands)7; P Dibbets-Schneider (Netherlands)8; MJJ Geelhoed (Netherlands)9; FL Stevens (Netherlands)3; MK Ninaber (Netherlands)1; LF de Geus-Oei (Netherlands)7 10 11;
1 - Department of Pulmonology, Leiden University Medical Center; 2 - Department of Medical Imaging, Radboud University Medical Center; 3 - Leiden University Medical Center; 4 - Department of Cardiology, Leiden University Medical Center; 5 - Department of Radiology, University Medical Center Utrecht; 6 - Department of Biomedical Data Sciences, Leiden University Medical Center; 7 - Department of Radiology, Leiden University Medical Center; 8 - : Department of Radiology, Leiden University Medical Center; 9 - Department of Pulmonology, St. Antonius Hospital, Nieuwegein; 10 - Biomedical Photonic Imaging Group, University of Twente; 11 - Department of Radiation Science & Technology, Delft University of Technology;
Keywords: Fasting protocol; FDG PET/CT; Myocardial suppression;
Select the theme: Cardiac Sarcoidosis
Type: Original Papers
Presentation: Poster Presentation

Introduction: Using [18F]FDG-PET/CT for assessment of cardiac sarcoidosis (CS) can be challenging due to physiological myocardial uptake. 

Objectives: We aimed to evaluate the effect of our current combined preparation strategy on semi-quantitatively assessed myocardial suppression in patients with suspected CS. 

Materials and Methods: Two groups were defined by fasting duration following a local protocol change in which the fasting period was extended from 12 to 18 hours. All patients followed a high-fat, low-carbohydrate (HFLC) diet for 24 hours. The 12-hour fasting group received unfractionated heparin (UFH) unless contraindicated, whereas the 18-hour fasting group received UFH only if it had been administered during prior examination. In total, 97 patients with suspected CS were included; 33 patients underwent both 12-hour and 18-hour preparation on subsequent scans. Physiological left ventricular uptake was assessed using a previously described standardized 6-point visual scoring system; (0, uptake less than ventricular blood pool; 1, uptake equal to ventricular blood pool; 2, uptake greater than blood pool but less than liver; 3, uptake equal to liver; 4, diffuse uptake greater than liver but less than twice liver uptake; 5, uptake greater than twice liver uptake).

Results: Myocardial FDG-uptake differed significantly between fasting protocols (p=0.006). Adequate suppression (visual score ≤2) was achieved in 89.1% of scans in the 18-hour fasting group, compared to 75.6% in the 12-hour fasting group, despite a significantly lower proportion of patients receiving UFH in the 18-hour group. Complete suppression (score ≤1) was observed in 84.8% and 73.2% of scans, respectively. Patients receiving heparin premedication had an independent odds ratio of 0.49 (95% CI: 0.23-1.04) for achieving a lower category of myocardial suppression.  

Conclusions: Our cohort study demonstrates that 18-hour fasting prior [18F]FDG-PET/CT improves myocardial suppression in patients evaluated for suspected CS, resulting in higher rates of adequate and complete myocardial suppression, despite significantly less frequent use of UFH.