Positron Emission Tomography for the Diagnosis of Immune Checkpoint Inhibitor-Related Myocarditis

Study Overview
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Brief Summary
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This study evaluates positron emission tomography for the diagnosis of immune checkpoint inhibitor-related myocarditis. Immune checkpoint inhibitors have shown promising results in various malignancies however, several immune related adverse events have been described of which myocarditis carries the highest reported mortality. Diagnostic procedures, such as positron emission tomography, help find and diagnose myocarditis and provide functional or disease activity information as opposed to the largely structural/anatomic information.

Detailed Description
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PRIMARY OBJECTIVE: I. To prospectively evaluate the sensitivity, specificity, positive predictive value, and negative predictive value of fludeoxyglucose F-18 (18 fluorodeoxyglucose) positive emission tomography computed tomography (PET CT) for the diagnosis of immune checkpoint inhibitor (ICI) related myocarditis. SECONDARY OBJECTIVES: I. To explore the clinical presentation and disease course of ICI-related myocarditis which include presenting symptoms (chest pain, dyspnea, fatigue), time from ICI initiation to symptom onset, hospitalization duration, time to peak troponin levels, and peak troponin levels. II. To evaluate biomarkers, including peak troponin, peak no probnp, admission troponin level, and admission nt probnp level, and imaging modalities of ICI-related myocarditis which include sensitivity, specificity, positive predictive value, and negative predictive value of cardiac magnetic resonance imaging (MRI). III. To determine the response to various treatments of ICI-related myocarditis which include time to resolution of symptoms, hospitalization duration, and peak troponin value stratified by treatment. IV. To observe the long-term outcomes, including late decline in left ventricular ejection fraction (LVEF) to < 50%, and survival after ICI related myocarditis, and monitoring of ICI-related myocarditis. V. To assess differences in PET CT imaging results between patients on steroid therapy versus not on steroid therapy for myocarditis. OUTLINE: Patients receive a low carbohydrate and high fat diet for 48-72 hours. Patients receive 18 fluorodeoxyglucose (FDG) then undergo PET CT.

Official Title
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Positron Emission Tomography for the Diagnosis of Immune Checkpoint Inhibitor-Related Myocarditis

Conditions
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Myocarditis Acute

Intervention / Treatment
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* Procedure: Computed Tomography
* Other: Fludeoxyglucose F-18
* Other: Low Carbohydrate High Fat Diet
* Procedure: Positron Emission Tomography


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients of age >= 18 years Patients must be able to understand and be willing to sign a written informed consent document. Surrogate decision-makers of patients will be allowed to consent patients for this study Patients must be receiving or have a history of receiving any ICI therapy in monotherapy or combination therapy Patients must have a suspicion of ICI-related myocarditis either by clinical presentation, biomarkers, or other diagnostic modalities Exclusion Criteria: Pregnant or lactating patients will be excluded

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Observational (diet, FDG PET CT)<br>Patients receive a low carbohydrate and high fat diet for 48-72 hours. Patients receive FDG then undergo PET CT. | Procedure: Computed Tomography<br>* Undergo FDG PET CT<br>* Other names: tomography;Other: Fludeoxyglucose F-18<br>* Undergo FDG PET CT<br>* Other names: Fluorodeoxyglucose F18;Other: Low Carbohydrate High Fat Diet<br>* low carbohydrate and high fat diet for 48-72 hours<br>Procedure: Positron Emission Tomography<br>* Undergo FDG PET CT<br>* Other names: proton magnetic resonance spectroscopic imaging;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sensitivity, specificity, positive predictive value, and negative predictive value | Calculations of sensitivity, specificity, positive predictive value, and negative predictive value and their 90% exact confidence intervals will be performed for the evaluation of positron emission tomography computed tomography considering endomyocardial biopsy as the gold standard. Secondary analysis of these parameters will be used considering the Bonaca et al diagnoses of immune checkpoint inhibitor (ICI)-related myocarditis as a new gold standard. Receiver operating characteristic (ROC) curve and the AUC value (area under the ROC curve) will be evaluated. | through study completion, an average of a year. |