Thursday, April 17, 2014
Marilynn Marchione / The Associated Press
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This Sept. 19, 2102, photo shows a linear accelerator used to treat cancer at a hospital in Johnstown, Pa. A new study shows radiation can hurt arteries, making them prone to harden and clog and cause a heart attack.
Most women treated today get doses that result in 1 to 5 gray units reaching the heart — more if the cancer is in the left breast. Patients in the study got an average of five gray units; the doses ranged from 1 to 28.
The risk of a heart attack, need for an artery-opening procedure or dying of heart disease rose about 7 percent per gray unit and no "safe" level was seen. The risk started to rise within five years of treatment and continued for at least 20 years.
What to do?
Don't forgo radiation if it's recommended because it is lifesaving and doctors increasingly have ways to shield the heart from exposure, said Dr. Bruce Haffty, associate director of the Cancer Institute of New Jersey and president-elect of ASTRO, the American Society for Radiation Oncology.
"Whatever cardiac risks may be there, they are outweighed by the cancer benefit," he said.
Some centers have special tables that women lie on face-down with holes for the breast to hang through. That allows radiation to be delivered just to that tissue rather than the wider chest area that gets irradiated when a woman lies face-up on a table.
Women need to tell any doctor treating them about radiation they have received in the past. It may mean they should avoid diagnostic tests that use radiation and instead have ultrasounds and MRI, or magnetic resonance imaging, whenever possible, Slosky said.
Some places are starting to use electronic medical records to track radiation exposure over a patient's lifetime, so the cumulative dose is known regardless of who ordered what test and when.
"I'd like to have a personal record like a personal dosimeter" for each patient, Slosky said. "Then you'd know" what risks they face and what tests are safe for them in the future.