Using FDG-PET imaging to diagnose subclinical myocarditis in cancer patients

Positron Emission Tomography for the Detection of Subclinical Immune Checkpoint Inhibitor-Induced Myocarditis (PET-SIM): A Prospective, Single Center, Single Arm, Open Label Pilot Study

Observational Mayo Clinic · NCT06566209

This study is testing if a special type of heart scan can help find early signs of heart inflammation in cancer patients using immune treatments.

Quick facts

Study typeObservational
Enrollment30 (estimated)
Ages18 Years and up
SexAll
SponsorMayo Clinic Academic / other
Locations1 site (Rochester, Minnesota)
Trial IDNCT06566209 on ClinicalTrials.gov

What this trial studies

This pilot study evaluates the effectiveness of Fluorodeoxyglucose - Positron Emission Tomography (FDG-PET) as a diagnostic tool for subclinical immune checkpoint inhibitor-induced myocarditis in patients with solid or hematologic malignancies. The study aims to determine if this condition is a distinct clinical entity that poses a risk of progression to more severe myocarditis. Participants will undergo specific dietary preparations and imaging procedures to assess their heart health and potential inflammation. The findings could lead to better risk stratification and management of patients receiving immune checkpoint inhibitors.

Who should consider this trial

Good fit: Ideal candidates include adults aged 18 and older with solid or hematologic malignancies who are undergoing treatment with immune checkpoint inhibitors.

Not a fit: Patients with a left ventricular ejection fraction below 45% or those with conclusive evidence of inflammation on cardiac MRI may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could improve early diagnosis and management of myocarditis in cancer patients, potentially preventing severe complications.

How similar studies have performed: While the use of FDG-PET in this specific context is novel, similar imaging modalities have shown promise in diagnosing myocarditis in other settings.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Age ≥18 years at the time of signing informed consent
* Any solid or hematologic malignancy undergoing treatment with ICI (either as a single agent or in combination with others)
* Ambulatory and able to complete a 48-72 hour high fat and low carbohydrate diet with 18 hours fasting (PET diet), 18F-FDG PET/CT scanning, as well as 13N-ammonia PET-CT myocardial perfusion imaging (part of the routine protocol of the investigation). These two studies will be done as part of the same imaging set.
* Willing to return to Mayo Clinic for ongoing follow-up
* Left ventricular ejection fraction (LVEF) ≥45%
* Cardiac MRI (CMR) without conclusive evidence of inflammation, coronary assessment available (either via cardiac computed tomography angiography, CCTA, or via coronary angiogram) Informed consent obtained before any trial-related activities. Trial-related activities are any procedures that are carried out as part of the trial, including activities to determine suitability for the trial.

Exclusion Criteria:

* Fulminant myocarditis requiring steroid therapy
* CMR with definitive evidence of myocarditis
* Clinical presentation consistent with acute coronary syndrome (wall motion abnormalities consistent with a specific coronary distribution, coronary angiogram with a culprit lesion identified, patients requiring revascularization either with percutaneous coronary interventions or coronary artery bypass grafting).
* Patients unable to provide informed consent
* Patients unable to complete the diet preparation protocol
* Pregnancy (all women of child-bearing age and potential will have a negative pregnancy test within 48 hours of the PET/CT at screen and 6-month visit)
* Breastfeeding

Where this trial is running

Rochester, Minnesota

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Subclinical Immune Checkpoint Inhibitor-Induced MyocarditisMyocarditisICI-MyocarditisSolid Malignant TumorHematologic MalignancySubclinical MyocarditisSubclinical ICI-myocarditis
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.