Cedars-Sinai researchers have identified a connection between radiation therapy exposure in specific regions of the heart and the development of heart arrhythmias in lung cancer patients. Radiation therapy is a standard treatment for advanced lung cancer, but it can lead to heart rhythm abnormalities, known as arrhythmias. A study published in the peer-reviewed journal JACC: CardioOncology reveals that investigators from Cedars-Sinai and Harvard University have developed a method to predict the type of arrhythmia based on the areas of the heart exposed to radiation. These insights could help radiation oncologists minimize the risk of arrhythmias in lung cancer patients and identify those who may require additional cardiac monitoring.
“In this study, radiation oncologists, cardiologists, electrophysiologists, and artificial intelligence specialists collaborated to map radiation exposure from lung cancer therapy to various regions of the heart,” said Dr. Katelyn Atkins, assistant professor of Radiation Oncology and Cardiology at Cedars-Sinai and the study’s first author. “We found that radiation exposure to critical structures like the pulmonary veins, coronary arteries, and atria was linked to specific types of arrhythmias, indicating unique injury pathways.”
The study included contributions from several authors, including Samuel C. Zhang, MD; Christopher Kehayias, PhD; and others. Funding for the research came from Dr. Raymond H. Mak, who received grants from AstraZeneca and ViewRay, and Dr. Anju Nohria, who has received support from Bristol Myers Squibb and consulting fees from several pharmaceutical companies.
Radiation therapy is crucial for treating lung cancer, but it poses risks to heart health. The study’s findings highlight the importance of understanding how radiation exposure can lead to arrhythmias, which can significantly impact patient outcomes.
Historically, many believed that cardiac complications from lung cancer treatment would not arise until several years after therapy.
However, the research team has shown that these complications can occur much sooner than previously thought.
“This paper builds on our earlier findings, focusing specifically on cardiac arrhythmias, whether they involve rapid or abnormal heartbeats,” Dr. Mak explained. “We have mapped radiation exposure to different parts of the heart to predict the risk of various arrhythmias.”
The team conducted a retrospective analysis of 748 patients with locally advanced non-small cell lung cancer who received radiation therapy. They calculated cardiac substructure dose parameters and used artificial intelligence tools to identify and measure radiation exposure to different heart areas, such as the pulmonary veins.
The study revealed that 17.1% of patients experienced grade 3 or greater arrhythmias, which are considered serious and may require hospitalization. The researchers also identified distinct arrhythmia classes linked to radiation doses to specific cardiac structures, including:
Atrial Fibrillation (AF): Associated with pulmonary vein dose.
Atrial Flutter: Linked to the left circumflex coronary artery dose.
Bradyarrhythmia: Connected to the right coronary artery dose.
Ventricular Tachyarrhythmia (VT) or asystole: Related to the left main coronary artery dose.
These findings could guide potential risk mitigation strategies for lung cancer patients undergoing radiation therapy.
“Now, when designing a radiation treatment plan for lung cancer patients, we recognize that certain areas, like the pulmonary veins, are critical risk predictors,” Dr. Mak said. “By avoiding excess radiation to these areas, we can reduce the likelihood of patients developing atrial fibrillation after treatment.”
The research team hopes that radiation oncologists will adopt these findings into their practice, leading to safer treatment protocols for lung cancer patients.
As awareness of the risks associated with radiation therapy grows, the collaboration between oncologists and cardiologists will be essential in improving patient care and outcomes.