Efficacity of Deep Inspiration Breath Hold and Intensity-modulated Radiotherapy in Preventing PErfusion Defect for Left Sided Breast Cancer (EDIPE)

In breast radiotherapy, especially for left sides breast cancers, the heart is the organ-at-risk which whose dose constraints are source of controversies. Historically breast cancer radiation therapy was associated with a significantly increased cardiac mortality. Two meta-analyses founded that the cardiac mortality risk was increased by 27% to 38%. This result is linked to outdated 2-D treatment techniques causing massive cardiac overexposure (Clarke M et al. 2005, Cheng YJ et al. 2017).

Three dimensional conformational radiotherapy reduced mean heart dose but the link between heart irradiation and radiation-induced heart damages doesn't seem to have threshold therefore to RHID is still a matter of concern (Darby SC et al. 2013; Taylor C et al. 2017).

The most used technique for breast cancer irradiation is opposite tangential field radiotherapy, however, it exposes the anterior interventricular coronary artery to a high dose during left breast irradiation (Nieder C et al. 2007). Therefore, radiotherapy techniques have developed to reduce cardiac exposure such as deep inspiration breath hold (DBIH) and intensity modulated radiation therapy (IMRT).

DBIH "mechanically" moves the heart away from the radiation beam and IMRT the dose distribution in the heart and reduces its exposure to high doses (Boda-Heggemann J et al. 2016, Lauche O et al. 2016).

Nevertheless, recent studies suggest that even with this level of cardiac exposure subclinical cardiac alterations may be detected, such as myocardial perfusion deficit (Eber et al. 2022; Marks LB et al. 2005; Gyenes G et al. 1997; Sioka C et al. 2011; Seddon B et al. 2002; Eftekhari M et al. 2015).