Subclinical Cardiac Damage Monitoring in Breast Cancer Patients Treated with an Anthracycline-Based Chemotherapy Receiving Left-Sided Breast Radiation Therapy: Subgroup Analysis from a Phase 3 Trial

This study, derived from the phase 3 SAFE trial (ClinicalTrials.gov identifier: NCT2236806), explores subclinical cardiac damage in breast cancer patients receiving anthracycline-based chemotherapy and left-sided breast radiation therapy (RT). Eligible patients were randomized to a cardioprotective pharmacological therapy (bisoprolol, ramipril, or both) or placebo, with cardiac surveillance at multiple time-point using standard and 3-dimensional echocardiography. Dosimetric parameters were analysed, including mean heart dose (MHD) and various metrics for heart substructures, employing advanced contouring techniques and auto-contouring software. In the analysis of left-sided breast RT patients, the study encompassed 39 out of 46 irradiated individuals, focusing on GLS and 3D-LVEF outcomes with ≥ 10