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The Future Of New Screening Technology: Is It Here...Or Is It Hype?
WDI newsletter Winter 2009
RIDGEWOOD, New Jersey — Every year in the United States, millions of women over the age of 40 go for an annual mammogram. The benefits are undeniable: since 1990, the rate of breast cancer mortality plummeted by 25 percent. While digital mammography is still the gold standard in screening technology, it does not find all breast cancers. New technologies are emerging that promise to make breast cancer detection even more accurate.
One of the most exciting new screening technologies is Molecular Breast Imaging (MBI), or Breast Specific Gamma Imaging (BSGI), the name used by its manufacturer, Dilon Technologies. Patients are injected with a short-acting radioactive tracing agent just prior to the exam. When the tracing agent is absorbed by breast tissue, abnormal cells absorb more of the tracer than healthy ones, making them clearly visible. The exam requires minimal compression and is not painful. Studies show molecular testing is proving to find a significant amount of additional cancers at an earlier stage.
Meanwhile, the number of indeterminate findings dropped by nearly 50 percent compared to Magnetic Resonance Imaging (MRI). MRI is highly sensitive and produces clear, detailed images, However, MRI has an elevated rate of false alarms, and insurance companies balk at covering them due to the high cost. MBI results in fewer callbacks and unnecessary biopsies at nearly one-third the cost of an MRI. While molecular testing is new for detecting breast cancer, it has been in use for over 20 years for cardiac stress tests, with proven benefits.
Another emerging new technology is called Digital Breast Tomosynthesis (DBT). Unlike the stationary mammogram, the tomosynthesis x-ray tub swings above the breast in narrow arcs to create a sequence of images. These images allow radiologists to “disassemble” the breast one layer at a time for a vastly more complete view.
Studies show that tomosynthesis may detect more cancers than conventional mammography, and may significantly reduce the number of biopsies needed, particularly when screening women with dense breasts.
But tomosynthesis has its drawbacks, too. Like the MRI, tomosynthesis is highly sensitive and tends to catch miniscule, though often harmless, details. Therefore, rather than solving one of MRI’s key limitations – excessive false positives – tomosynthesis may actually increase the rate.
Another concern is the number of images each exam produces. Mammograms generate two images per breast; DBT produces approximately fifty images. A four-scan exam could generate more than two hundred. Having so much to study could add days to the time needed to present results, a considerable step backward from the virtually instant results of current digital systems. The FDA is now evaluating tomosynthesis; the first commercial systems are expected to appear in the next several years.
The new technologies on the horizon are intriguing, but not all are ready for prime time. Overly sensitive or difficult to read scans present a whole new set of problems. Even so, the future of breast cancer screening is moving us closer to more accurate, more proactive healthcare for all women.
Women’s Health Imaging Quarterly is published four times a year by Women’s Digital Imaging of Ridgewood, New Jersey, a private practice led by Dr. Lisa Weinstock, specializing in detecting and diagnosing conditions such as breast cancer, gynecologic diseases and osteoporosis. WDI offers a comfortable, private environment, the accuracy of the most advanced diagnostic instruments, and exceptional care from compassionate, highly qualified female doctors.
© Copyright 2008 Women’s Digital Imaging of Ridgewood, New Jersey, All Rights Reserved
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