MAMMOGRAMS AND OTHER BREAST IMAGING IN WOMEN WITH IMPLANTS

Some women have expressed concern that the presence of an implant will make it difficult or impossible to use mammography for the early detection of breast cancer. The committee reviewed available literature on the use of mammography in women with implants and also examined the usefulness of other imaging techniques for the detection of implant rupture.

Mammograms—x-rays of the breast—have proved their value in finding breast cancer in its early stages. Randomized, controlled trials have confirmed that mammography significantly decreases breast cancer death rates.

Women with cosmetic breast implants undergo mammography and other imaging techniques just as do women without implants. In general, however, mammography is not necessary for reconstructed breasts because the breast tissue has been removed.

Questions have come up about the possibility that the implant itself might obscure some breast tissue in augmented breasts, making an early diagnosis of breast cancer by mammography more difficult. No studies of women with breast implants have shown increases in cancer deaths because of mammographic diagnostic delay. A large study of women with implants for augmentation actually showed fewer new cases of cancer than would be expected and also found the severity (stage) of these cancers at diagnosis to be about the same among women with and without implants. But the committee believes this question deserves further study.

The mammogram is an extremely important screening technique for finding breast cancer. All women in the age and risk categories appropriate for regular mammograms should continue to have them. The IOM committee realizes, however, that breasts augmented with implants can pose unique imaging problems, and that the success of the mammography depends in part on the experience and expertise of the technician.

Many women (about 40,000 in 1994, according to one report) had implants removed when questions about their safety arose and attracted adverse publicity. When an implant is removed (explanted), there is a chance that scar tissue will form in the breast area and show up on the mammogram as a suspicious mass.

Another possible problem for the radiologist concerns the textured shells used in many implants today, the surface of which may fill with tissue and mimic a rupture on the film. The capsule around the implant can



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M AMMOGRAMS AND OTHER BREAST IMAGING IN WOMEN WITH IMPLANTS Some women have expressed concern that the presence of an implant will make it difficult or impossible to use mammography for the early detection of breast cancer. The committee reviewed available literature on the use of mammography in women with implants and also examined the usefulness of other imaging techniques for the detection of implant rupture. Mammograms—x-rays of the breast—have proved their value in finding breast cancer in its early stages. Randomized, controlled trials have confirmed that mammography significantly decreases breast cancer death rates. Women with cosmetic breast implants undergo mammography and other imaging techniques just as do women without implants. In general, however, mammography is not necessary for reconstructed breasts because the breast tissue has been removed. Questions have come up about the possibility that the implant itself might obscure some breast tissue in augmented breasts, making an early diagnosis of breast cancer by mammography more difficult. No studies of women with breast implants have shown increases in cancer deaths because of mammographic diagnostic delay. A large study of women with implants for augmentation actually showed fewer new cases of cancer than would be expected and also found the severity (stage) of these cancers at diagnosis to be about the same among women with and without implants. But the committee believes this question deserves further study. The mammogram is an extremely important screening technique for finding breast cancer. All women in the age and risk categories appropriate for regular mammograms should continue to have them. The IOM committee realizes, however, that breasts augmented with implants can pose unique imaging problems, and that the success of the mammography depends in part on the experience and expertise of the technician. Many women (about 40,000 in 1994, according to one report) had implants removed when questions about their safety arose and attracted adverse publicity. When an implant is removed (explanted), there is a chance that scar tissue will form in the breast area and show up on the mammogram as a suspicious mass. Another possible problem for the radiologist concerns the textured shells used in many implants today, the surface of which may fill with tissue and mimic a rupture on the film. The capsule around the implant can 21

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also calcify and resemble the small calcifications often associated with cancer cells. Or, worse, calcifications that are associated with cancer may look harmless. Capsular contracture can make it harder to obtain a good x-ray of breast tissue. The folds that can develop around the shell may also make diagnosis of implant rupture difficult. To make mammograms more readable, some researchers have been investigating implant fillers that may be more x-ray friendly. Materials studied include peanut and soy bean oils. So far, there is insufficient evidence about their effectiveness and safety. Many of the concerns about implants and mammograms arose in the 1960s and 1970s when both mammograms and silicone breast implants were in their infancy. Since then, both mammograms and implants have improved. Mammography now achieves more sophisticated imaging, and in 1988, a more advanced technique was introduced for manipulating the implant without compressing it. Although mammography may present some problems, the IOM committee recommends its use and notes that the procedure is quick and inexpensive. The committee suggests that women and their doctors consider submuscular implant placement, which makes diagnosis by mammography much easier and puts it more on a par with that available to women without implants. Updated techniques include avoiding unnecessary compression, with only enough pressure to keep the breast and implant from moving. The committee finds mammography of limited value in detecting rup- tures, particularly those contained inside the implant capsule. Even with extracapsular rupture, mammography can only diagnose the presence of silicone outside the capsule. On a positive note, the report finds little evidence that procedures involving mammography cause ruptures. Use of Ultrasound to Detect Implant Ruptures Ultrasound uses a scanning device that converts an electrical current into high-frequency sound waves as it passes over the skin. The echoes of these waves form a pattern on a TV-like monitor. Ultrasound works par- ticularly well in viewing soft tissue and fluids and is often used as a follow- up to suspicious findings on mammograms. A “snowstorm” effect on the monitor screen may indicate silicone gel outside the implant, a sign of rupture. When there is a capsular contracture, however, ultrasound may 22

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not reliably determine whether a rupture is present, nor can it “see” the back of the implant. Although ultrasound is inexpensive and can detect many ruptures, its reliability is highly dependent on the operator’s skills. Use of Magnetic Resonance Imaging to Detect Implant Ruptures Magnetic resonance imaging (MRI) provides high-quality cross-sectional images of the inside of the body without the use of x-rays. This imaging device can be used to detect the presence of silicone gel and is the diagnostic tool of choice when mammography or sonograms suggest an implant rupture. MRI is the most accurate imaging technique for determining whether an implant is intact. The procedure is most effective when the magnetic resonance coils are specifically designed for the breast. Such modern MRI screening is a highly sensitive and specific test for ruptures. MRI screening, however, is expensive and time consuming. The committee recommends more investigation into whether routine screening for ruptures should be done for women without any symptoms. Such a study should answer the question of whether all ruptures should necessi- tate having the implant and capsule removed, a procedure requiring an operation and possible tissue loss. 23