The impact of high and low cardiac substructure dose levels on cardiac toxicity in lung and breast cancer radiotherapy

Abstract

With improved survival outcomes of patients with cancer, cardiovascular diseases have become an important part of morbidity and mortality. In recent years, there has been much interest in the literature on the impact of radiotherapy on the late cardiac toxicity. Various cardiac dose-volume constraints have been reported in association with cardiovascular events and mortality, but without consistent constraint. Low-dose heart exposure in adjuvant breast cancer radiotherapy can lead to important cardiac events in decade or more after treatment. However, in radical lung cancer radiotherapy, high-dose heart exposure can lead to increased cardiovascular mortality in the first years after treatment. We can further influence the survival of patients with cancer after chest irradiation by lowering the absorbed dose to the heart, which is already made possible by better irradiation techniques and image-guided radiotherapy. Additional benefits can be gained by better understanding and considering the impact of radiation on individual cardiac structures, also in connection with other patients’ comorbidities, and by close cardiac follow-up of patients after chest radiation therapy.