Krannert Institute of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana.
Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
Int J Radiat Oncol Biol Phys. 2021 Apr 1;109(5):1301-1310. doi: 10.1016/j.ijrobp.2020.12.008. Epub 2020 Dec 17.
To characterize the early changes in echocardiographically derived measures of cardiac function with contemporary radiation therapy (RT) in breast cancer and to determine the associations with radiation dose-volume metrics, including mean heart dose (MHD).
In a prospective longitudinal cohort study of 86 patients with breast cancer treated with photon or proton thoracic RT, clinical and echocardiographic data were assessed at 3 time points: within 4 weeks before RT initiation (T0), within 3 days before 6 weeks after the end of RT (T1), and 5 to 9 months after RT completion (T2). Associations between MHD and echocardiographically derived measures of cardiac function were assessed using generalized estimating equations to define the acute (T0 to T1) and subacute (T0 to T2) changes in cardiac function.
The median estimates of MHD were 139 cGy (interquartile range, 99-249 cGy). In evaluating the acute changes in left ventricular ejection fraction (LVEF) from T0 to T1, and accounting for the time from RT, age, race, preexisting cardiovascular disease, and an interaction term with anthracycline or trastuzumab exposure and MHD, there was a modest decrease in LVEF of borderline significance (0.22%; 95% confidence interval [CI], -0.44% to 0.01%; P = .06) per 30-day interval for every 100 cGy increase of MHD. Similarly, there was a modest worsening in longitudinal strain (0.19%; 95% CI, -0.01% to 0.39%; P = .06) per 30-day interval for each 100 cGy increase in MHD. We did not find significant associations between MHD and changes in circumferential strain or diastolic function.
With modern radiation planning techniques, there are modest subclinical changes in measures of cardiac function in the short-term. Longer-term follow-up studies are needed to determine whether these early changes are associated with the development of overt cardiac disease.
描述乳腺癌现代放射治疗（RT）过程中心脏功能超声指标的早期变化，并确定与辐射剂量-体积参数的相关性，包括平均心脏剂量（MHD）。
在一项前瞻性纵向队列研究中，对 86 例接受光子或质子胸部 RT 的乳腺癌患者，在 RT 开始前 4 周内（T0）、RT 结束后 6 周内的 3 天内（T1）和 RT 完成后 5-9 个月（T2），评估临床和超声心动图数据。使用广义估计方程评估 MHD 与心脏功能超声指标之间的相关性，以定义心脏功能的急性（T0 至 T1）和亚急性（T0 至 T2）变化。
MHD 的中位数估计值为 139 cGy（四分位距 99-249 cGy）。在评估从 T0 到 T1 的左心室射血分数（LVEF）的急性变化，并考虑 RT 时间、年龄、种族、既往心血管疾病以及与蒽环类药物或曲妥珠单抗暴露的交互项和 MHD 时，LVEF 略有下降（0.22%；95%置信区间[CI]，-0.44%至 0.01%；P =.06），MHD 每增加 100 cGy，间隔 30 天。同样，MHD 每增加 100 cGy，纵向应变（0.19%；95%CI，-0.01%至 0.39%；P =.06）也略有恶化，间隔 30 天。我们没有发现 MHD 与圆周应变或舒张功能变化之间存在显著相关性。
采用现代放射治疗计划技术，心脏功能的短期亚临床指标有适度变化。需要进行长期随访研究，以确定这些早期变化是否与明显的心脏疾病发展有关。
