Quantitative assessment of radiotherapy-induced myocardial damage using MRI: a systematic review

Abstract

Purpose To determine the role of magnetic resonance imaging (MRI)-based metrics to quantify myocardial toxicity following radiotherapy (RT) in human subjects through review of current literature. Methods Twenty-one MRI studies published between 2011-2022 were identified from available databases. Patients received chest irradiation with/without other treatments for various malignancies including breast, lung, esophageal cancer, Hodgkin’s, and non-Hodgkin’s lymphoma. In 11 longitudinal studies, the sample size, mean heart dose, and follow-up times ranged from 10-81 patients, 2.0-13.9 Gy, and 0-24 months after RT (in addition to a pre-RT assessment), respectively. In 10 cross-sectional studies, the sample size, mean heart dose, and follow-up times ranged from 5-80 patients, 2.1-22.9 Gy, and 2-24 years from RT completion, respectively. Global metrics of left ventricle ejection fraction (LVEF) and mass/dimensions of cardiac chambers were recorded, along with global/regional values of T1/T2 signal, extracellular volume (ECV), late gadolinium enhancement (LGE), and circumferential/radial/longitudinal strain. Results LVEF tended to decline at >20 years follow-up and in patients treated with older RT techniques. Changes in global strain were observed after shorter follow-up (13±2 months) for concurrent chemoradiotherapy. In concurrent treatments with longer follow-up (8.3 years), increases in left ventricle (LV) mass index were correlated with LV mean dose. In pediatric patients, increases in LV diastolic volume were correlated with heart/LV dose at 2 years post-RT. Regional changes were observed earlier post-RT. Dose-dependent responses were reported for several parameters, including: increased T1 signal in high-dose regions, a 0.136% increase of ECV per Gy, progressive increase of LGE with increasing dose at regions receiving >30 Gy, and correlation between increases in LV scarring volume and LV mean/V10/V25 Gy dose. Conclusion Global metrics only detected changes over longer follow-up, in older RT techniques, in concurrent treatments, and in pediatric patients. In contrast, regional measurements detected myocardial damage at shorter follow-up and in RT treatments without concurrent treatment and had greater potential for dose-dependent response. The early detection of regional changes suggests the importance of regional quantification of RT-induced myocardial toxicity at early stages, before damage becomes irreversible. Further works with homogeneous cohorts are required to examine this matter.

Spectrum of Imaging Patterns of Lung Cancer following Radiation Therapy

“…MRI is not currently commonly used in the assessment of post-radiation changes [38]. MRI is sometimes used following lung radiotherapy in the evaluation of cardiac toxicity [39]. Recent animal studies suggest that using MRI following the administration of hyperpolarized noble gases may prove beneficial in assessing alveolar and metabolic damage in lung tissue [40].…”

Early Effects of Modern Radiotherapy for Lung Cancer on Endothelial Damage and Myocardial Fibrosis: A Prospective Single-Center Study

“…In turn, in the case of computed tomography, ionizing radiation is used, which must be considered for serial follow-up and in the cases involving young patients. In the case of magnetic resonance imaging, the limitations are price, availability, and several contraindications to the examination (for instance, claustrophobia or magnetic-resonance-incompatible implants) [ 7 ]. For this reason, for a long time, researchers have been focusing on identifying laboratory markers that could be used in the early diagnosis of complications of radiotherapy, such as myocardial fibrosis or endothelial dysfunction.…”