BACKGROUND Patients with left-sided breast cancer have an increased risk of cardiovascular disease (CVD) after radiotherapy (RT). While the awareness of cardiac toxicity has increased enormously over the last decade, the role of individual baseline cardiac risks has not yet been systematically investigated. Aim of the present study was to evaluate the impact of baseline CVD risks on radiation-induced cardiac toxicity. METHODS Two hundred ten patients with left-sided breast cancer treated in the prospective Save-Heart Study using a deep inspiration breath-hold (DIBH) technique were analysed regarding baseline risk factors for CVD. Three frequently used prediction tools (Procam, Framingham and Reynolds score) were applied to evaluate the individual CVD risk profiles. Moreover, 10-year CVD excess absolute risks (EAR) were estimated using the individual mean heart dose (MHD) of treatment plans in free breathing (FB) and DIBH. RESULTS The individual baseline CVD risk factors had a strong impact on the 10-year cumulative CVD risk. The mean baseline risks of the non-diabetic cohort (n = 200) ranged from 3.11 to 3.58%, depending on the risk estimation tool. A large number of the non-diabetic patients had a very low 10-year CVD baseline risk of ≤1%; nevertheless, 8-9% of patients reached ≥10% baseline 10-year CVD risk. In contrast, diabetic patients (n = 10) had significantly higher baseline CVD risks (range: 11.76-24.23%). The mean 10-year cumulative risk (Framingham score) following RT was 3.73% using the DIBH-technique (MHD:1.42Gy) and 3.94% in FB (MHD:2.33Gy), after adding a 10-year-EAR of + 0.34%(DIBH) and + 0.55%(FB) to the baseline risks, respectively. Smoking status was one of the most important and modifiable baseline risk factors. After DIBH-RT, the 182 non-smoking patients had a mean 10-year cumulative risk of 3.55% (3.20% baseline risk, 0.35% EAR) as compared to 6.07% (5.60% baseline risk, 0.47% EAR) for the 28 smokers. CONCLUSION In the present study, all CVD prediction tools showed comparable results and could easily be integrated into daily clinical practice. A systematic evaluation and screening helps to identify high-risk patients who may benefit from primary prevention. This could result in an even higher benefit than from heart-sparing irradiation techniques alone.

中文翻译：

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保留心脏的放射疗法在乳腺癌中：基线心脏风险的重要性。

背景技术患有左侧乳腺癌的患者在放射治疗（RT）后具有增加的心血管疾病（CVD）风险。在过去的十年中，尽管人们对心脏毒性的认识大大增加，但尚未对基线个人心脏风险的作用进行系统的研究。本研究的目的是评估基线CVD风险对辐射诱发的心脏毒性的影响。方法对前瞻性Save-Heart研究中使用深吸气屏气（DIBH）技术治疗的210例左侧乳腺癌患者的CVD基线危险因素进行了分析。应用了三种常用的预测工具（Procam，Framingham和Reynolds评分）来评估各个CVD风险状况。此外，使用自由呼吸（FB）和DIBH中治疗计划的个人平均心脏剂量（MHD）估算10年CVD超额绝对风险（EAR）。结果个体基线CVD危险因素对10年累积CVD危险有很大影响。非糖尿病人群（n = 200）的平均基线风险范围为3.11至3.58％，具体取决于风险评估工具。大量非糖尿病患者的10年CVD基线风险非常低，≤1％。尽管如此，仍有8-9％的患者达到10年基线CVD风险≥10％。相反，糖尿病患者（n = 10）的基线CVD风险明显更高（范围：11.76-24.23％）。使用DIBH技术（MHD：1.42Gy），RT后平均10年累积风险（Framingham评分）为3.73％，而FB（MHD：2.33Gy）为3.94％，再加上10年EAR + 0.34 ％（DIBH）和+ 0。分别达到基线风险的55％（FB）。吸烟状况是最重要且可修改的基线危险因素之一。在进行DIBH-RT后，182名非吸烟患者的10年平均累积风险为3.55％（基线风险3.20％，EAR为0.35％），而28位患者为6.07％（基线风险5.60％，EAR为0.47％）。吸烟者。结论在本研究中，所有CVD预测工具均显示出可比的结果，并且可以轻松地整合到日常临床实践中。系统的评估和筛查有助于确定可能从一级预防中受益的高危患者。与仅保留心脏的照射技术相比，这可能会带来更高的收益。182名非吸烟患者的10年平均累积风险为3.55％（基准风险为3.20％，EAR为0.35％），而28名吸烟者的平均十年累积风险为6.07％（基准风险为5.60％，EAR为0.47％）。结论在本研究中，所有CVD预测工具均显示出可比的结果，并且可以轻松地整合到日常临床实践中。系统的评估和筛查有助于确定可能从一级预防中受益的高危患者。与仅保留心脏的照射技术相比，这可能会带来更高的收益。182名非吸烟患者的10年平均累积风险为3.55％（基准风险为3.20％，EAR为0.35％），而28名吸烟者的平均十年累积风险为6.07％（基准风险为5.60％，EAR为0.47％）。结论在本研究中，所有CVD预测工具均显示出可比的结果，并且可以轻松地整合到日常临床实践中。系统的评估和筛查有助于确定可能从一级预防中受益的高危患者。与仅保留心脏的照射技术相比，这可能会带来更高的收益。系统的评估和筛查有助于识别可能从一级预防中受益的高危患者。与仅保留心脏的照射技术相比，这可能会带来更高的收益。系统的评估和筛查有助于确定可能从一级预防中受益的高危患者。与仅保留心脏的照射技术相比，这可能会带来更高的收益。