Coronary Artery Dose-Volume Parameters Predict Risk of Calcification After Radiation Therapy

Abstract

BACKGROUNDRadiation exposure increases the risk of coronary artery disease (CAD). We explored the association of CAD with coronary artery dose-volume parameters in patients treated with 3D-planned radiation therapy (RT).METHODSPatients who received thoracic RT and were evaluated by cardiac computed tomography ≥ 1 year later were included. Demographic data and cardiac risk factors were retrospectively collected. Dosimetric data (mean heart dose, dmax, dmean, V50 - V5) were collected for the whole heart and for each coronary artery. A coronary artery calcium (CAC) Agatston score was calculated on a per-coronary basis and as a total score. Multivariable generalized linear mixed models were generated. The predicted probabilities were used for receiver operating characteristic analyses.RESULTSTwenty patients with a median age of 53 years at the time of RT were included. Nine patients (45%) had ≥ 3/6 conventional cardiac risk factors. Patients received RT for breast cancer (10, 50%), lung cancer (6, 30%), or lymphoma/myeloma (4, 20%) with a median dose of 60 Gy. CAC scans were performed a median of 32 months after RT. CAC score was significantly associated with radiation dose and presence of diabetes. In a multivariable model adjusted for diabetes, segmental coronary artery dosimetric parameters (dmax, dmean, V50, V40 V30, V20, V10, and V5) were significantly associated with CAC score > 0. V50 had the highest area under the ROC curve (0.89, 95% confidence interval, 0.80-0.97).CONCLUSIONSCoronary artery radiation exposure is strongly correlated with subsequent segmental CAC score. Coronary calcification may occur soon after RT and in individuals with conventional cardiac risk factors.

Advances in Preclinical Research Models of Radiation-Induced Cardiac Toxicity

“…While in previous clinical studies, mean heart dose was related to the likelihood of RIHD [12], and the risk of major coronary events in breast cancer patients increased linearly by approximately 4-16% for each 1 Gy in mean heart dose received [6,9,10], other studies have shown that dose to the coronary arteries may also be an indicator of risk of developing coronary artery stenosis, an important aspect of RIHD [73]. Thus, there is a need for irradiation of small segments of the heart in pre-clinical models, which may include key sections of coronary arteries, to accurately predict risk factors and successfully develop interventions in RIHD [64,[74][75][76][77][78]. Partial heart irradiation in small animals may also be used to elucidate ways in which high-dose radiation treatment of segments of the heart can decrease ventricular tachycardia events in patients [79].…”

Preventive Cardio-Oncology: The Time Has Come

“…Non-invasive stress testing could also be considered every 5 years, along with a concomitant transthoracic echocardiogram, for those who received radiation therapy (3,158). Most recently, a study illustrated a strong correlation between coronary artery radiation exposure and subsequent segmental coronary artery calcification scores (169). New coronary artery calcification was noted in some patients with breast cancer, lung cancer, lymphoma, or myeloma at a median of 32 months after radiation therapy.…”

Emerging Challenges of Radiation-Associated Cardiovascular Dysfunction (RACVD) in Modern Radiation Oncology: Clinical Practice, Bench Investigation, and Multidisciplinary Care

“…based on data estimated from conventional tangential technique (21, 92-94). Nevertheless, attenuating IR doses to coronary artery (95-97) and other cardiac substructures, such as left anterior descending artery (LAD) and left ventricle (LV), are more reasonable and suitable in modern precise RT departments (2,66,95,98). However, long-term results investigated dose effects on these cardiac substructures are pending.…”