Linda Burroughs has walked the halls of Dartmouth-Hitchcock Medical Center in Lebanon, N.H., more times than she'd prefer in the last 18 months. A diagnosis of early breast cancer last April caught her by surprise.
"I was shocked. I've never had a call back. Never been asked to return," Burroughs said.
A routine mammogram showed cancer in her right breast. A biopsy confirmed it and surgery was scheduled. But just a few days before her scheduled lumpectomy, Dr. Steven Poplack, the director of breast imaging at Dartmouth, called her back for an experimental 3-D mammogram on her left breast. A traditional 2-D image had shown no cancer there, but the doctor was suspicious.
"Who knew that mammograms were 2-D? Did you ever stop to think about it? I never did," Burroughs said.
Well, she knows the difference now. The 3-D image-- called tomosynthesis-- found a small cancer in her left breast, as well. Burroughs was one of Dartmouth's first 50 clinical trial patients.
Here's how tomosynthesis works. The breast is still put into compression and an X-ray is obtained. The difference is the X-ray machine moves in a short arc and as it moves it takes multiple exposures that are reconstructed into thin slices and put together like a movie. Doctors can then page through 1 millimeter layers of the breast, similar to a CAT scan.
"This is the angled side view and this is the top down view. This is the traditional two-dimensional mammogram and I do not see a cancer on this. I would have read this as normal," Poplack said.
Now switch to 3-D on the same patient and play the movie.
"You can see these little lines radiating into this one little point here. See these little lines coming in here. So that's a sign of cancer on a mammogram, which we couldn't appreciate on the 2-D part of the exam," Poplack explained.
Poplack says the benefits of 3-D imaging are clear and women with denser breasts-- and those who've never had a mammogram before-- will benefit the most. The goal is to find previously undetectable, early stage cancers and also reduce the number of women-- about 10 percent-- who are called back on false alarms.
As for the risks, the dose of radiation from 3-D is twice as much.
"For this current technology there is more radiation experienced. It's about twice the dose of a usual digital mammogram. That's still well within the dose limit set by the government-- the Mammography Quality Standards Act of 1996. So the dose, while higher, is still acceptable," Poplack said.
As for the future, Poplack believes tomosynthesis will eventually become routine for all women being screened for breast cancer.
"I think you'll see over the next five to 10 years that 3-D will replace 2-D," he said.
And for people like Linda Burroughs, that couldn't happen soon enough.
"I'm confident that it contributed to making my life far better than it would have been had I not been diagnosed in the left breast and had I gone for a year, who knows what would have happened," she said.
A new technology that caught a cancer and changed her life.
Dartmouth-Hitchcock was one of just five sites nationwide to conduct clinical trials on 3-D mammograms. They are now available at hospitals across the country, including Fletcher Allen Health Care in Burlington.
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