Whole heart radiotherapy in advanced heart failure: is there a role?
Heart failure is a highly morbid medical condition that causes a global decrease in the heart's ability to function effectively. Chronic inflammation is recognized as a major pathway for this disease, and in its end-stage, there are limited effective treatment options. Emerging data suggest that focal, high-dose cardiac radiotherapy for ventricular arrhythmias (VT) is relatively safe and may improve electrical conductivity and suppress negative cardiac remodelling mechanisms driven by chronic inflammation. With the evolving experience of radiotherapy in VT, it has been observed that in a subset of patients who also have heart failure, the left ventricular ejection fraction (LVEF) - a marker of global cardiac function - may also improve following this treatment. The primary hypothesis for this effect is that, while regions of the heart are targeted with high doses of radiation, the rest of the heart receives a low dose of radiation, which may have anti-inflammatory effects, as seen in other benign diseases, but the true mechanism is currently unknown. Recent animal models evaluating this observation demonstrated that 5 Gy of whole heart radiotherapy was sufficient to improve the LVEF in different causes of heart failure. Based on these findings, we designed one of the first phase 1 clinical trials evaluating the use of whole-heart radiotherapy as a therapeutic treatment in end-stage heart failure. We hypothesize that 5 Gy whole heart radiotherapy is a safe treatment that may improve LVEF and decrease blood markers of heart failure and inflammation. In this talk, I will focus on some of the biological and biophysical underpinnings of cardiac radiotherapy that motivate our clinical trial, and I will provide a thorough overview of the technical and physical challenges of administering such a treatment, which is a remarkable interdisciplinary collaboration between radiation oncologists, cardiologists, and, of course, medical physicists.
Bio
Dr. Ian Gerard is a hepatobiliary and gastrointestinal radiation oncology fellow at the Princess Margaret Cancer Centre, working with Professor Laura A. Dawson. Dr. Gerard completed his medical and residency training at McGill University. Prior to medical training, he pursued a bachelor’s degree in medical biophysics at Western University, followed by a master's degree in medical radiation physics at McGill University. He then completed his PhD in biomedical engineering under James McGill Professor, Dr. Louis Collins, at the Montreal Neurological Institute at McGill University, focusing on improving the accuracy of image-guided neurosurgical tools for brain cancers. Dr. Gerard has more than 60 scientific publications and over 1000 total citations in his early career and has received numerous grants, awards, and distinctions that recognize his clinical, research, and educational contributions since 2007. His current research interests lie in the clinical and translational science of hepatobiliary and gastrointestinal malignancies, and he is involved in numerous ongoing clinical trials evaluating different radiation therapy techniques to treat these cancers. Additionally, he is actively involved in numerous high-impact studies and ongoing clinical trials in the field of cardiac radiotherapy using stereotactic ablative radiotherapy for the treatment of cardiac arrhythmias and low-dose radiotherapy for congestive heart failure. He is one of the co-founders of the McGill Cardiac Radioablation In Cardiomyocytes network whose mission is to champion translational medicine in cardiac radiotherapy.