AbstractBackgroundRacial disparities in survival of patients with cancer motivate research to quantify treatment disparities and evaluate multilevel determinants. Previous research has not evaluated cardiac radiation dose in large cohorts of breast cancer patients by race nor examined potential causes or implications of dose disparities.MethodsWe used a statewide consortium database to consecutively sample 8750 women who received whole breast radiotherapy between 2012 and 2018. We generated laterality- and fractionation-specific models of mean heart dose. We generated patient- and facility-level models to estimate race-specific cardiac doses. We incorporated our data into models to estimate disparities in ischemic cardiac event development and death. All statistical tests were 2-sided.ResultsBlack and Asian race independently predicted higher mean heart dose for most laterality-fractionation groups, with disparities of up to 0.42 Gy for Black women and 0.32 Gy for Asian women (left-sided disease and conventional fractionation: 2.13 Gy for Black women vs 1.71 Gy for White women, P < .001, 2-sided; left-sided disease and accelerated fractionation: 1.59 Gy for Asian women vs 1.27 Gy for White women, P = .002). Patient clustering within facilities explained 22%-30% of the variability in heart dose. The cardiac dose disparities translated to estimated excesses of up to 2.6 cardiac events and 1.3 deaths per 1000 Black women and 0.7 cardiac events and 0.3 deaths per 1000 Asian women vs White women.ConclusionsDepending on laterality and fractionation, Asian women and Black women experience higher cardiac doses than White women. This may translate into excess radiation-associated ischemic cardiac events and deaths. Solutions include addressing inequities in baseline cardiac risk factors and facility-level availability and use of radiation technologies.

中文翻译：

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全乳放疗患者心脏剂量种族差异的中介因素

摘要背景癌症患者生存率的种族差异促使研究人员量化治疗差异并评估多层次的决定因素。先前的研究尚未按种族评估大量乳腺癌患者的心脏辐射剂量，也未检查剂量差异的潜在原因或影响。方法我们使用全州联盟数据库对 2012 年至 2018 年间接受全乳放疗的 8750 名女性进行了连续抽样。我们生成了平均心脏剂量的偏侧性和分次特异性模型。我们生成了患者和设施级别的模型来估计特定种族的心脏剂量。我们将数据纳入模型中，以估计缺血性心脏事件发生和死亡的差异。所有统计检验都是双面的。结果黑人和亚洲人种独立预测大多数偏侧分割组的平均心脏剂量较高，黑人女性的差异高达 0.42 Gy，亚洲女性为 0.32 Gy（左侧疾病和传统分割：黑人女性为 2.13 Gy vs 1.71 Gy）对于白人女性，P < .001，2侧；左侧疾病和加速分割：亚洲女性为 1.59 Gy，而白人女性为 1.27 Gy，P = .002)。设施内的患者聚集解释了 22%-30% 的心脏剂量变异性。与白人女性相比，心脏剂量差异预计每 1000 名黑人女性会发生最多 2.6 起心脏事件和 1.3 例死亡，每 1000 名亚洲女性会发生 0.7 例心脏事件和 0.3 例死亡。结论根据偏侧性和分割情况，亚洲女性和黑人女性比白人女性承受的心脏剂量更高。这可能会导致过量辐射相关的缺血性心脏事件和死亡。解决方案包括解决基线心脏危险因素以及设施水平可用性和辐射技术使用方面的不平等问题。