Post Treatment Health: The Landscape
Presentation 3: Cardiovascular Effects of Radiation Therapy
Ming Hui Chen, M.D., M.M.Sc.
Associate Director, Non-Invasive Cardiac Laboratory
Department of Medicine
Brigham and Women’s Hospital and Dana-Farber Cancer Institute
- Patients receiving treatment for Hodgkin’s disease and left breast cancer have the highest risk of damage to the cardiovascular system. This risk is a result of the large amounts of radiation to the chest involved in the treatment of Hodgkin’s disease patients, and the location of the left breast directly over the heart.
- Hodgkin’s disease survivors are two to seven times more likely to suffer a fatal cardiac event; left breast cancer survivors are two times more likely. Survivors also have an increased risk of stroke due to damage to major blood vessels (i.e., increased tendency to develop atherosclerosis, a thickening and hardening of the arteries due to buildup of cholesterol and other cellular debris).
- Risk of cardiac problems depends on the type of cancer treatment (e.g., radiation dosage, area of the body irradiated) but also is affected by general cardiac disease risk factors including age, gender, lipid profile, body mass index (BMI), and physical activity.
- Effects of radiation on the heart include thickening of the pericardium (lining of the heart), stiffening of cardiac valves, damage to the heart muscle resulting in contraction problems, damage to coronary arteries, and atherosclerosis of the aorta and the vessels supplying blood to the head.
- Pericarditis (inflammation and thickening of the pericardium) is the most common cardiac effect, with thickening seen in 5 to 20 percent of survivors. It is not easily detected; often, the only symptom is shortness of breath, which can have a negative effect on quality-of-life. Sudden death from coronary artery disease also is common, and is seen in 10 percent of Hodgkin’s disease survivors by approximately 9 years after treatment.
- One method to lessen the damage to the heart by radiation therapy is to instruct patients receiving radiation to draw in a deep breath at the time of radiation, which moves the heart out of the field of radiation and decreases the amount of radiation the heart receives. This technique also decreases the volume of healthy lung tissue exposed to radiation.