The risk of cardiovascular toxicity caused by cancer radiotherapy—a narrative review

Background and Objective: Radiotherapy is an efficient treatment for cancer. However, some cancer survivors who receive thoracic radiotherapy experience radiation-induced cardiovascular toxicity, leading to long-term impact on cardiovascular health. This review summarizes the current literature regarding the basic pathogenic mechanisms, development, and prevention of radiation-induced cardiovascular toxicity. Methods: A literature search was performed on PubMed to find reported histological observations and studies on acute and late cardiovascular toxicity in cancer patients treated with radiotherapy. A systematized review of articles on the present topic published between May 1967 and April 2021 was carried out. Key Content and Findings: Since 1967, heart disease following cancer radiotherapy was increasingly being reported. The development of cardiovascular toxicity among cancer survivors receiving mediastinal radiation correlates primarily with the total dose of mediastinal radiation received, total heart dose, and the dose of radiation per fraction. Modern radiotherapy techniques such as intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) in the respiratory-gated radiotherapy in deep-inspiration breath-hold (DIBH) position achieve a considerable dose sparing to the heart and reduce mean heart dose. Modern irradiation techniques in combination with cardio-oncology will help to optimize the care of patients with cancer. Conclusions: Improvements in radiotherapy planning have reduced the volume of the heart and major coronary vessels to be exposed to high doses. Reducing the risk of cardiovascular toxicity caused by cancer radiotherapy is urgent because it is an important cause of morbidity and mortality in survivors.