Skyttä Tanja, Tuohinen Suvi, Boman Eeva, Virtanen Vesa, Raatikainen Pekka, Kellokumpu-Lehtinen Pirkko-Liisa
Department of Oncology and School of Medicine, Tampere University Hospital, University of Tampere, 33521, Tampere, Finland.
Heart Center Co and School of Medicine, University of Tampere, Tampere University Hospital, Tampere, Finland.
Radiat Oncol. 2015 Jul 10;10:141. doi: 10.1186/s13014-015-0436-2.
Adjuvant radiotherapy (RT) for left-sided breast cancer increases cardiac morbidity and mortality. For the heart, no safe radiation threshold has been established. Troponin T is a sensitive marker of myocardial damage. Our aim was to evaluate the effect of left-sided breast cancer RT on serum high sensitivity troponin T (hscTnT) levels and its association with cardiac radiation doses and echocardiographic parameters.
A total of 58 patients with an early stage, left-sided breast cancer or ductal carcinoma in situ (DCIS) who received adjuvant breast RT without prior chemotherapy were included in this prospective, non-randomized study. Serum samples were taken before, during and after RT. An increase of hscTnT >30 % was predefined as significant. A comprehensive 2D echocardiograph and electrocardiogram (ECG) were performed before and after RT. Dose-volume histograms (DVHs) were generated for different cardiac structures.
The hscTnT increased during RT from baseline in 12/58 patients (21 %). Patients with increased hscTnT values (group A, N = 12) had significantly higher radiation doses for the whole heart (p = 0.02) and left ventricle (p = 0.03) than patients without hscTnT increase (group B, N = 46). For the left anterior descending artery (LAD), differences between groups A and B were found in volumes receiving 15 Gy (p = 0.03) and 20 Gy (p = 0.03) Furthermore, after RT, the interventricular septum thickened (p = 0.01), and the deceleration time was prolonged (p = 0.008) more in group A than in group B.
The increase in hscTnT level during adjuvant RT was positively associated with the cardiac radiation doses for the whole heart and LV in chemotherapy-naive breast cancer patients. Whether these acute subclinical changes increase the risk of excessive long-term cardiovascular morbidity or mortality, will be addressed in the follow-up of our patients.
左侧乳腺癌的辅助放疗会增加心脏发病率和死亡率。对于心脏，尚未确定安全的辐射阈值。肌钙蛋白T是心肌损伤的敏感标志物。我们的目的是评估左侧乳腺癌放疗对血清高敏肌钙蛋白T（hscTnT）水平的影响及其与心脏辐射剂量和超声心动图参数的关联。
本前瞻性、非随机研究纳入了58例早期左侧乳腺癌或原位导管癌（DCIS）患者，这些患者在未接受过化疗的情况下接受了辅助乳腺放疗。在放疗前、放疗期间和放疗后采集血清样本。hscTnT升高>30%被预先定义为显著升高。在放疗前后进行全面的二维超声心动图和心电图（ECG）检查。为不同的心脏结构生成剂量体积直方图（DVH）。
在放疗期间，12/58例患者（21%）的hscTnT从基线水平升高。hscTnT值升高的患者（A组，N = 12）全心脏（p = 0.02）和左心室（p = 0.03）接受的辐射剂量显著高于hscTnT未升高的患者（B组，N = 46）。对于左前降支动脉（LAD），A组和B组在接受15 Gy（p = 0.03）和20 Gy（p = 0.03）的体积上存在差异。此外，放疗后，A组的室间隔增厚（p = 0.01），减速时间延长（p = 0.008），且比B组更明显。
在未接受化疗的乳腺癌患者中，辅助放疗期间hscTnT水平的升高与全心脏和左心室的心脏辐射剂量呈正相关。这些急性亚临床变化是否会增加长期心血管疾病过度发病或死亡的风险，将在我们患者的随访中进行研究。
