Radiation Exposure of Cardiac Conduction Nodes During Breast Proton Therapy

Abstract Purpose The exposition of cardiac conduction system during breast radiation therapy has never been studied, despite the increasing use intensity-modulated therapy, which exposes larger volume to low-dose bath. We evaluated node exposure irradiation with volumetric modulated arc and estimated potential dosimetric benefit proton therapy. Materials Methods Atrioventricular (AVN) sinoatrial (SAN) nodes were retrospectively delineated according published guidelines on simulation computed tomography scans 12 cancer patients having undergone conserving surgery adjuvant locoregional Intensity-modulated treatment was replanned for all patients. Mean maximum doses delivered SAN AVN retrieved compared. Correlation coefficients calculated between or whole heart. Results Average mean 2.8 2.3 Gy, respectively, left-sided 9.6 3.6 right-sided irradiation. 3.5 Gy 13.1 4.6 significantly reduced AVN. Correlations heart usually significant. Conclusion can be substantially exposed especially Cardiotoxicity studies evaluating might define dose constraints criteria additional cardiac-sparing techniques, such as respiratory techniques could underlying rhythmic disorders.