Pilot Study of Biomarkers and Cardiac MRI as Early Indicators of Cardiac Exposure Following Breast Radiotherapy

Cardiac MRI has increasing utility in evaluating structural and functional cardiac pathologies. For detection of coronary artery disease, MRI outperforms SPECT and dobutamine stress echocardiography for the detection of ischemia. MRI also can detect wall-motion abnormalities and other dysfunction. Dynamic contrast-enhanced MRI (DCE-MRI) can evaluate microvascular parameters such as vessel permeability and fluid volume fraction as an assessment of tissue perfusion. Thus, cardiac MRI holds promise for early detection of subclinical cardiac abnormalities after radiotherapy and could potentially identify patients for intervention to prevent cardiac events. All patients will follow the protocol calendar requiring research MRIs, but will receive standard radiation treatment determined by their treating physician. In this study, treatment will not be altered based on the data collected from these MRIs.

"Scant data exist on potential biomarkers of cardiac radiation exposure and damage. However, we have identified potential candidates based on other processes affecting heart function in a way similar to probable mechanisms of RT-related injury. For fibrosis and left ventricular dysfunction, these include galectin-3 and N-terminal-Pro brain natriuretic peptide. For myocyte destruction, troponin; for inflammation and oxidative stress, C-reactive protein, myeloperoxidase, and growth differentiation factor 15. Additional blood will be collected and stored for future assessment of other candidate biomarkers.~All patients will follow the calendar of protocol required research blood draws for biomarker collection, but will receive standard radiation treatment as clinically indicated by their treating physician. In this study, treatment will not be altered based upon the data collected from these samples."