Abstract
Background Breast cancer is the second most common cancer worldwide. Thanks to the modern oncological treatments, disease specific survival has improved throughout the last decades. The number of breast cancer survivors has been increasing, and more and more attention has been paid to the breast cancer treatment side effects. Whereas there are many data regarding ischemic heart disease after radiotherapy for breast cancer, there is not much data in the literature about the incidence and clinical meaning of pericardial disease after breast cancer radiotherapy. Conclusions Although radiation-induced pericarditis is the earliest form of radiation-induced cardiovascular disease after irradiation of the heart, it seems that in clinical practice, especially by using modern radiotherapy treatment techniques, it is underdiagnosed because patients are mostly asymptomatic. In some cases, especially in its late form and after multimodal systemic oncological treatment in combination with radiotherapy, it could be presented in severe form and life threatening. Treatment modalities for radiation-induced pericardial diseases are the same as in the non-irradiated population, but in the irradiated patients, surgery may be difficult.