Walker Valentin, Lairez Olivier, Fondard Olivier, Jimenez Gaëlle, Camilleri Jérémy, Panh Loïc, Broggio David, Bernier Marie-Odile, Laurier Dominique, Ferrières Jean, Jacob Sophie
Pôle Santé-Environnement (PSE-SANTE), Service de recherche sur les effets biologiques et sanitaires des rayonnements ionisants (SESANE), Laboratoire d'épidémiologie des rayonnements ionisants (LEPID), Institute for Radiological Protection and Nuclear Safety (IRSN), BP17, 92262, Fontenay-aux-Roses cedex, France.
Department of Cardiology, Rangueil University Hospital, 31059, Toulouse, France.
Radiat Oncol. 2020 Aug 20;15(1):201. doi: 10.1186/s13014-020-01635-y.
Radiotherapy for breast cancer (BC) and its resulting cardiac exposure are associated with subclinical left ventricular dysfunction characterized by early decrease of global longitudinal strain (LS) measurement based on 2D speckle-tracking echocardiography. Recent software allows multi-layer and segmental analysis of strain, which may be of interest to quantify and locate the impact of cardiac exposure on myocardial function and potentially increase the early detection of radiation-induced cardiotoxicity. The aim of the study was to evaluate whether decrease in LS 6 months after radiotherapy is layer-specific and if it varies according to the left ventricular regional level and the coronary arterial territories.
LS was measured at baseline before radiotherapy and 6 months post-radiotherapy. The LS was obtained for each myocardial layer (endocardial, mid-myocardial, epicardial), left ventricular regional level (basal, mid, apical) and coronary artery territory (left anterior descending artery (LAD), circumflex artery, right coronary artery).
The study included 64 left-sided BC patients. Mean age was 58 years, mean doses to the heart, the left ventricle and the LAD were respectively 3.0, 6.7 and 16.4 Gy. The absolute decrease of LS was significant for the three layers (endocardial: - 20.0 ± 3.2% to - 18.8 ± 3.8%; mid-myocardial: - 16.0 ± 2.7% to - 15.0 ± 3.1%; epicardial: - 12.3 ± 2.5% to - 11.4 ± 2.8%, all p = 0.02), but only the relative decrease of LS in the endocardial layer was close to be significant (- 4.7%, p = 0.05). More precisely, the LS of the endocardial layer was significantly decreased for the most exposed parts of the left ventricle corresponding to the apical level (- 26.3 ± 6.0% vs. -24.2 ± 7.1%, p = 0.03) and LAD territory (- 22.8 ± 4.0% vs. -21.4 ± 4.8%, p = 0.03).
Six months post-radiotherapy, LS decreased predominantly in the endocardial layer of the most exposed part of the left ventricle. For precise evaluation of radiotherapy-induced cardiotoxicity and early left ventricular dysfunction, the endocardial layer-based LS might be the most sensitive parameter.
ClinicalTrials.gov: NCT02605512 , Registered 6 November 2015 - Retrospectively registered.
乳腺癌放疗及其所致心脏受照与亚临床左心室功能障碍相关，其特征为基于二维斑点追踪超声心动图的整体纵向应变（LS）测量值早期下降。近期软件可进行应变的多层和节段分析，这对于量化和定位心脏受照对心肌功能的影响以及可能提高放射性心脏毒性的早期检测可能具有重要意义。本研究的目的是评估放疗后6个月LS的下降是否具有层特异性，以及其是否根据左心室区域水平和冠状动脉区域而有所不同。
在放疗前基线和放疗后6个月测量LS。获取每个心肌层（心内膜、心肌中层、心外膜）、左心室区域水平（基底、中间、心尖）和冠状动脉区域（左前降支动脉（LAD）、回旋支动脉、右冠状动脉）的LS。
该研究纳入了64例左侧乳腺癌患者。平均年龄为58岁，心脏、左心室和LAD的平均剂量分别为3.0、6.7和16.4 Gy。三层的LS绝对下降均具有显著性（心内膜：从-20.0±3.2%降至-18.8±3.8%；心肌中层：从-16.0±2.7%降至-15.0±3.1%；心外膜：从-12.3±2.5%降至-11.4±2.8%，所有p = 0.02），但仅心内膜层LS的相对下降接近显著性（-4.7%，p = 0.05）。更确切地说，左心室最暴露部分的心内膜层LS在对应心尖水平（-26.3±6.0%对-24.2±7.1%，p = 0.03）和LAD区域（-22.8±4.0%对-21.4±4.8%，p = 0.03）显著下降。
放疗后6个月，LS主要在左心室最暴露部分的心内膜层下降。对于精确评估放疗引起的心脏毒性和早期左心室功能障碍，基于心内膜层的LS可能是最敏感的参数。
ClinicalTrials.gov：NCT02605512，于2015年11月6日注册 - 回顾性注册。
