We all know the urgent need for the development of better screening tools for breast cancer. Our current choices: mammography, MRI, and ultrasound all have limitations and none are 100 percent accurate. There especially is ongoing controversy about the value of mammograms in early detection and saving lives. If you somehow have missed this, check out this article from ncpa.org.
3D mammograms are the newest entry into the screening world. Not yet widely available, there is also dissension or concern about their value. The biggest worry is that they expose women to twice as much radiation as other types of mammograms. Since the technology is so new, not all insurance companies will pay for these scans. Dr Susan Love points out that the real test of any screening tool is not just whether it finds cancer, but whether it saves lives. There have not been long term studies to test this vis à vis these new machines, and she feels it is unlikely that the manufacturer will pay to sponsor them. Here is an article that clearly lays out the pros and cons:
Q. What is a 3D mammogram?
A. The technology, called tomosynthesis, provides three dimensional images of the breast by using a technology similar to CT scans, or computed tomography, says Carol Lee, a radiologist at New York's Memorial SloanKettering Cancer Center and chair of the American College of Radiology's breast imaging commission. The imaging machine moves around the breast in an arc, taking multiple X-rays that a computer forms into a 3D image. The Food and Drug Administration approved tomosynthesis last year and it's now used in 46 states, according to Hologic, which manufactures the machines.
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And from a Washington Post article:
"The 3-D image doesn't replace the standard 2-D mammogram," says Julianne Greenberg, a radiologist at Washington Radiology Associates, which has begun telling women who come in for their standard 2-D screening that they can add a 3-D mammogram to it for $50. "Three-D is added value to an already existing, really good technology."
In a conventional mammogram, the breasts are compressed and X-rayed four times: side to side and top to bottom, for both the left and the right breast. To take the 3-D images, an arm of the machine sweeps in an arc around the breast during each of the four compressions, taking anywhere from 20 to 60 pictures to produce a 3-D rendering of the breast. These images look almost like holograms; radiologists can spin and flip them around on a computer screen, searching for cancer in the tissue and lymph nodes.
When looking at a 2-D and a 3-D image of a breast together, radiologists showed a 7 percent improvement in their ability to distinguish between cancerous and non cancerous tumors.
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