Radiation Damage to the Heart After Treatment

John Han-Chih Chang, MD and Kenneth Blank, MD
Last Modified: November 1, 2001

Dear OncoLink "Ask the Experts,"
I have heard that radiation of the left breast following lumpectomy for DCIS may damage one's heart. Is this true? If so, what are the odds of heart damage for a patient choosing radiation for DCIS?  
Thank You,

John Han-Chih Chang, MD and Kenneth Blank, MD, Editorial Assistants for Oncolink, respond:

Thank you for your interest and question.

Anytime radiation is given to the left side of the chest there may be a dose of radiation to the heart. The possible side effects may be:

  • irritation/inflammation of the lining of the heart (pericarditis)
  • fluid accumulation around the heart
  • microvascular disease of the coronary vessels causing increased atherosclerosis or cardiac muscle scarring

Radiation to the left breast or chest wall enters at an angle. This significantly minimizes the dose to the heart and lungs. In the past, when the treatment machines and planning systems were not as sophisticated, there were significant amounts of cardiac morbidity as mentioned above. Currently however, in the age of megavoltage machines and 3 dimensional treatment planning, treatment of the left breast has rarely accounted for any cardiac difficulties. The risk of heart damage is difficult to quantify, but in most recent studies, it is well below 5% (some less than 1%). With proper planning, cardiac problems are rarely an issue.


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