The impact of proton therapy on cardiotoxicity following radiation treatment

Cardiac disease following radiation therapy represents a major consideration in the treatment of a variety of malignancies. Damage to the heart can manifest in a variety of pathologies including ischemic cardiac disease, cardiomyopathy, valvular dysfunction, arrhythmias, and pericarditis. This damage has been shown to directly relate to cardiac radiation dose and to stem from a range of cellular pathways that are often related to fibrosis. The importance of minimizing radiation dose to the heart is especially critical in the pediatric population and when treating disease sites adjacent to the heart. Proton therapy represents a promising approach to minimize dose to normal tissues such as the heart. The cardiac dosimetry reductions due to proton therapy have been demonstrated in multiple cancers and further long-term follow-up will determine the clinical significance of these reductions to cardiac structures. Future approaches using advanced techniques such as FLASH therapy could provide even further benefit by reducing post-radiation fibrosis.