Radiation therapy CAD risk assessment remains a critical concern for clinicians managing breast cancer survivors. While older techniques posed significant risks, modern protocols aim to spare cardiac tissue. Therefore, researchers conducted a retrospective case-control study to evaluate heart health using coronary CT angiography (CTA). The study compared patients who received radiation therapy (RT) with a matched control group to identify potential long-term damage.
Assessing Plaque and Stenosis
The research team evaluated several parameters, including coronary artery calcium (CAC) scores and high-risk plaque (HRP) phenotypes. Interestingly, the results showed no evidence of a difference in CAC scores between the RT and control groups. Specifically, the RT group recorded a mean score of 201.1 Agatston units (AU) while the control group showed 75.4 AU. Furthermore, the rate of obstructive disease remained similar in both cohorts. Consequently, the study suggests that RT may not lead to more severe coronary stenosis in this specific population.
Radiation Therapy CAD Risk and Laterality
Clinicians often suspect that left-sided radiation poses a higher threat due to the heart’s anatomical position. However, this study found no significant difference between left versus right RT for CAC scores or stenosis severity. Additionally, the rate of high-risk plaque phenotypes remained comparable across both groups. This finding provides some reassurance regarding the safety of modern lateralized radiation fields. Nevertheless, regular monitoring remains essential for ensuring optimal long-term health outcomes in cancer survivors.
Structural and Valvular Observations
In addition to coronary arteries, the study investigated valvular fibrosis and calcifications. The prevalence of these findings was generally low in both examined groups. However, researchers did observe a 1.4-fold higher prevalence of fibrous adherence in the RT group compared to controls. This structural change primarily affected the left anterior descending or right coronary artery. Ultimately, the conclusion indicates that RT for breast cancer does not associate with more severe coronary disease in this cohort.
Frequently Asked Questions
Q1: Does modern radiation therapy significantly increase the risk of coronary artery blockages?
Based on this study, modern radiation therapy for breast cancer does not show a significant association with more severe coronary stenosis or high-risk plaque phenotypes compared to a control group.
Q2: Is there a difference in heart risk between left-sided and right-sided breast cancer radiation?
The study found no evidence of a significant difference in coronary artery disease profiles or calcium scores between patients receiving left-sided versus right-sided radiation therapy.
References
- Deeg J et al. Impact of Radiation Therapy for Breast Cancer on the Coronary Artery Disease Profile at Cardiac CT. Radiol Cardiothorac Imaging. 2026 Apr undefined. doi: 10.1148/ryct.250415. PMID: 41885623.
- Berlin E et al. Breast Cancer Radiotherapy Leads to Moderate Cardiac Function Decline Over Years. JACC: CardioOncology. 2025 Jun.
- Zhang R et al. Long-Term Cardiovascular Risk After Radiotherapy in Women With Breast Cancer. J Am Heart Assoc. 2017 May.