Multimodal assessment of acute cardiac toxicity induced by thoracic radiotherapy in cancer patients. Study protocol

Assessment of left heart dysfunction to predict doxorubicin cardiotoxicity in children with lymphoma

Objectives

The objectives of this study were to assess the changes in the left myocardial function after chemotherapy for childhood lymphoma and observe the predictive or monitor value for cancer treatment-related cardiac dysfunction (CTRCD) by speckle-tracking echocardiography.

Methods

A total of 23 children with histopathological diagnoses of lymphoma were included, with age-matched normal controls. Comparative analysis of clinical serological tests and left heart strain parameters in children with lymphoma, including left ventricular global longitudinal strain (LVGLS); global myocardial work (GMW) indices, which include global work index (GWI), global constructive work (GCW), global wasted work, and global work efficiency; and the LS of subendocardial, middle, and subepicardial layer myocardium during left ventricular systole were measured: left atrial strain of reservoir phase (LASr), left atrial strain of conduit phase (LAScd), and left atrial strain of contraction phase (LASct).

Results

One-way ANOVA showed that GLS, GWI, GCW, LASr, and LAScd were closely associated with CTRCD and multivariate logistic regression analysis showed that GLS was the most sensitive predictor for detecting patients at lofty risk of anthracycline-related cardiotoxicity. Both before and after chemotherapy, GLS in the left ventricle showed a pattern of basal segment < middle segment < apical segment and subepicardial < middle < subendocardial layer (p < 0.05), and the degree of decrease also showed a regular pattern of epicardial layer < middle layer < subendocardial layer while the difference was not significant (p > 0.05). After chemotherapy, maximum flow rate in early mitral relaxation/left atrial systolic maximum flow rate (E/A) and left atrial volume index of each group were in the normal range, and the values of LASr, LAScd, and LASct slightly increased in the second cycle and decreased significantly in the fourth cycle after chemotherapy, reaching the lowest level; LASr and LAScd were positively correlated with GLS.

Conclusion

LVGLS is a more sensitive and earlier indicator to predict CTRCD compared with conventional echocardiography-related parameters and serological markers, and GLS of each myocardial layer showed a certain regularity. Left atrial strain can be used for early monitoring of cardiotoxicity in children with lymphoma after chemotherapy.

Radiotherapy-Induced Cardiotoxicity: The Role of Multimodality Cardiovascular Imaging

Radiotherapy (RT) is one of the pillars of cancer therapy. High-dose radiation exposure on the thorax is mainly used in the context of adjuvant RT after breast surgery, in lung and esophageal cancer, and as a complement to systemic treatment in lymphoma. Due to the anatomical proximity, the heart inevitably receives some radiation that can result in acute and chronic cardiotoxicity, leading to heart failure, coronary artery disease, pericardial and valvular heart disease. Current evidence suggests there is no safe radiation dose to the heart, which poses a need for early recognition of RT-induced cardiac injury to initiate cardioprotective treatment and prevent further damage. Multimodality cardiac imaging provides a powerful tool to screen for structural and functional abnormalities secondary to RT. Left ventricular ejection fraction, preferably with three-dimensional echocardiography or cardiovascular magnetic resonance (CMR), and global longitudinal strain with speckle-tracking echocardiography are currently the key parameters to detect cardiotoxicity. However, several novel imaging parameters are tested in the ongoing clinical trials. CMR parametric imaging holds much promise as T1, T2 mapping and extracellular volume quantification allow us to monitor edema, inflammation and fibrosis, which are fundamental processes in RT-induced cardiotoxicity. Moreover, the association between serum biomarkers, genetic polymorphisms and the risk of developing cardiovascular disease after chest RT has been demonstrated, providing a platform for an integrative screening approach for cardiotoxicity. The present review summarizes contemporary evidence of RT-induced cardiac injury obtained from multimodality imaging—echocardiography, cardiovascular computed tomography, CMR and nuclear cardiology. Moreover, it identifies gaps in our current knowledge and highlights future perspectives to screen for RT-induced cardiotoxicity.