Summary
In the multimodality treatment of breast cancer, adjuvant radiotherapy (RT) has an important role in
achieving local control and increasing survival. Cardiac toxicity due to breast RT, especially left-sided
breast RT, is rare but clearly recognizable. As overall survival rates are steadily increasing, long-term
toxicities also become increasingly important in terms of late cardiac events, possibly caused by RT.
Even small doses for the heart are thought to increase the risk of cardiac toxicity. Advanced radiation
techniques such as intensity-modulated radiation therapy, volumetric-modulated arc RT, deep inspiration
breath-hold techniques, and prone positioning for pendular breast can eliminate the heart from
the primary beams. In addition to mean heart dose, breast cancer RT planning should also include
constraints for cardiac subvolumes. Especially for patients who have pre-existing such as cardiovascular
disease, diabetes mellitus, dyslipidemia, arterial hypertension, lifestyle factor (tobacco smoking, alcohol,
physical inactivity, and poor nutrition), and physicians have to be careful about cardiotoxicity. Radiation
oncologists and cardiology specialists should provide closely cooperating regular and long-term followup.
This will provide the improvement of patient outcomes.
