Review questions diagnostic value of MRI scans to detect rupture of silicone breast implants

The U.S. Food and Drug Administration currently recommends regular follow-up magnetic resonance imaging (MRI) scans for women with silicone breast implants. But a new review shows significant flaws in the evidence supporting this recommendation, reports the March issue of Plastic and Reconstructive Surgery®, the official medical journal of the American Society of Plastic Surgeons (ASPS).

Because of these scientific limitations, the available data may overestimate the ability of MRI to detect ruptured breast implants—particularly when scans are performed for screening purposes in symptom-free women. The study was led by Dr. Jae W. Song of University of Michigan, Ann Arbor.

Review Questions Diagnostic Value of Screening MRI Scans
The researchers reviewed 21 studies evaluating MRI and/or ultrasound to detect rupture of silicone breast implants. Although the FDA recommends MRI, some physicians prefer ultrasound for screening purposes.

The combined data suggested that MRI was fairly accurate in detecting implant-related problems. However, it was much more likely to detect problems in women with implant-related symptoms: 14 times more likely than in women without symptoms. Even in a mixed "screening sample"—consisting of some women with and some without symptoms—the detection rate was twice as high as in asymptomatic women.

Because most of the women in the studies had symptoms, the true accuracy of MRI for detecting implant-related problems in asymptomatic women was likely much lower. For ultrasound, reported accuracy rates varied widely.

Silicone breasts implants have been extensively studied due to concerns about possible adverse health effects. Based on reports linking ruptured implants to autoimmune diseases, the FDA banned silicone implants in 1992. The ban was lifted in 2006, when repeated studies failed to confirm the association with autoimmune diseases.

However, the FDA recommended that women undergo regular MRI scans in the years after surgery to screen for implant rupture. Given that more than 1.25 million American women have received silicone implants, it's important to evaluate the evidence that MRI is an effective screening test.

The study raises important questions about the accuracy of MRI scanning, especially in women without symptoms. Beyond the issue of accuracy, the authors note that screening tests are generally performed to detect diseases with serious consequences—whereas the health risks associated with ruptured silicone implants, if any, are still unknown.

The researchers also note that in reported cases of implant rupture, the average age of the implants is over 10 years. Dr. Song and coauthors write, "[T]he benefits of screening within the first 10 years are unclear, and the effectiveness of such a screening program warrants further investigation." Further studies are also needed to evaluate the long-term health effects of ruptured silicone breast implants, the effectiveness of MRI or other screening tests, and the costs of and patient preferences for screening.