Role of Speckle tracking echocardiography in the early cardiotoxicity detection after breast radiotherapy

Abstract

Cardiotoxicity following breast cancer radiotherapy (RT) is one of the major side effects. The Global longitudinal strain measurement (GLS) based on 2D speckle tracking imaging (STI) allows detection of left ventricular (LV) dysfunction at a subclinical stage. The aim of the study is to detect patients at risk of cardiotoxicity using STI and to determine the correlation between segmental RT doses and sub-clinical cardiotoxicity. All patients received 3D conformal RT. The STI was performed prior to RT and then 3, 6 and 12 months after. A LV GLS impairment was defined as a reduction of more than 10% from the initial value. A qualitative evaluation of the Bull's eye alteration of different segments was also performed. Independent-sample T test was used to compare mean doses of RT according to the alteration of the different segments. From June 2017 to August 2018, a total of 103 female patients were included. Sixty patients had left sided RT and 95 patients received chemotherapy prior to RT. Seven patients (7.8%) presented a LV GLS impairment. During the follow-up, the LV strain alterations predominated in the anteroseptal and apical LV segments. The mean radiation doses in LV segments with altered strain values was significantly higher than in non-altered segments (6.7-8.2 Gy vs. 4.9-5.4 Gy; P < 0.05). The Results of our study show that radiation dose is correlated with the subclinical LV segments’ alteration. STI with global and segmental strain analysis is an important tool to detect early sub-clinical cardio-toxicity.