NCT03048097

Optimizing Acquisition Parameters and Interpretive Methods of FDG-PET/CT With Rb-82

Optimizing Acquisition Parameters and Interpretive Methods of FDG-PET/CT With Rb-82 Myocardial Perfusion Imaging for Evaluation of Cardiac Sarcoidosis

• Status: Completed
• Phase: EARLY_Phase 1
• Study type: Interventional
• Enrollment: 15 (actual)
• Sponsor: Yale University · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

In this this investigation, 15 subjects with a high probability of cardiac sarcoidosis based on clinical criteria and abnormal cardiac FDG uptake on initial, clinically indicted FDG PET study will be considered for this study. The study will test the following Aims: Aim 1. Effect of FDG incubation time on visual and quantitative interpretation of FDG uptake. Changes in incubation time can affect imaging target:background ratios and study sensitivity/specificity. For the study-directed exam, all patients will undergo sequential cardiacfocused FDG-PET imaging at 90 and 120 minutes after injection of FDG. Imaging variables will be evaluated as below. Aim 2. Reproducibility of FDG and Rb82 PET findings on sequential imaging. It is unknown whether FDG-positive imaging findings in cardiac sarcoidosis are reproducible. All patients will undergo study-directed FDG-PET/CT with MPI imaging within approximately 2 weeks from initial clinical scan.

Detailed description

Sarcoidosis is a systemic disease of unknown etiology characterized by non-caseating granulomatous inflammation. The pathophysiologic features of cardiac sarcoidosis include macrophage-induced, T-cell mediated non-caseating granulomatous inflammation, followed by myocardial scarring/fibrosis with clinical sequelae including arrhythmias, conduction abnormalities, and contractile dysfunction. These lead to high event rates in patients with cardiac sarcoidosis, with several studies reporting a prevalence of ventricular tachycardia ranging from 23% to 38% and an \~ 20% rate of clinical congestive heart failure. FDG-PET/CT with Rb82 myocardial perfusion imaging (FDG-PET with MPI) is becoming the gold standard imaging technique for evaluating the degree of inflammation and the response to immunosuppressive treatment in patients with cardiac sarcoidosis. FDG PET imaging allows for evaluation of inflammatory macrophage infiltration, while Rb82 MPI allows for determination of myocardial scar burden. Despite emerging data from our center and others on the clinical utility of this technique in predicting prognosis, there is little consensus on the reproducibility of this technique or optimal imaging acquisition techniques and interpretative strategies. In this study, patients with a high clinical likelihood of cardiac sarcoidosis will undergo a study-directed FDG PET/CT with Rb82 myocardial perfusion imaging study approximately 2 weeks following an initial clinically-directed examination. The two FDG PET with MPI examinations will be examined for reproducibility of imaging findings, including: SUVmax, SUVmean, distribution of FDG uptake, extra cardiac FDG uptake, SUVvolume, SUVvolume:intensity, perfusion defect size/severity/location, LV ejection fraction, myocardial blood flow. Strict attention will be paid to ensure patients undergo the same metabolic preparation prior to the two examinations.

Conditions

• Sarcoidosis

Interventions

Type	Name	Description
DRUG	Fluorodeoxyglucose	a radiopharmaceutical used in the medical imaging modality positron emission tomography (PET)
DRUG	Rubidium	used in PET scans
DIAGNOSTIC_TEST	FDG-PET/CT with Rb82 Myocardial Perfusion Imaging	A 18-20 gauge catheter equipped with a 3-way stopcock will be inserted preferably in the antecubital vein. Cardiac FDG-PET imaging will be performed on the YNHH GE Discovery ST PET/CT scanner following a high fat/low carbohydrate diet and a prolonged fast as is current clinical protocol. Resting ECG-gated dynamic Rb-82 PET imaging will be performed using 20-30 mCi of Rb82 as per YNHH clinical imaging protocol and established clinical guidelines. FDG-PET imaging will be performed following a high fat/low carbohydrate diet (instructions provided to patient) and a fast of greater than 12 hours. The patient will be injected with the same dose of FDG (8-10mCi) as they received for their index clinical examination. Cardiac FDG imaging will be performed using a single 3D acquisition over the heart. Low-dose CT images (120 kV, 50-150 mA based on BMI) for the purposes of attenuation correction will be performed before Rb82 and FDG imaging sequences.

Timeline

• Start date: 2017-02-01
• Primary completion: 2018-07-02
• Completion: 2018-07-02
• First posted: 2017-02-09
• Last updated: 2019-08-26

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated drug study