Can painless infrared scans replace mammograms? Not at all, says FDA
Women are being warned to not be misled by websites touting infrared imaging technology as an alternative to mammograms for breast cancer screening.
Websites that tout "thermography" make it sound as if it's the perfect alternative to breast-squashing mammographic X-rays: no pain, no radiation, and it can find breast cancer years before mammography.
Don't be misled, says the U.S. Food and Drug Administration. Thermography, which uses infrared imaging to show patterns of heat near the surface of the body, is not a substitute for mammography, and does not improve detection.
"In fact, the greatest danger from thermography is that those who opt for this method instead of mammography may miss the chance to detect cancer at its earliest stage," the FDA said in its latest consumer health alert, issued Oct. 27.
Since 2011, the FDA has been taking action — mostly, sending warning letters — to crack down on health-care providers and thermography manufacturers "who try to mislead patients into believing that thermography can take the place of mammography."
Thermography has not undergone rigorous human testing to prove safety and effectiveness. The FDA has "cleared" the technology, meaning newer infrared camera-and-software systems are deemed equivalent to the first one, introduced in 1982. Thermography is cleared as a supplement, or "adjunct," to mammography, but health insurers don't cover it because it's unproven.
The mammogram, which compresses the patient's breast while a burst of X-rays pass through it, "still is the best tool for breast cancer screening," declared the FDA alert.
This year happens to be the 25th anniversary of the federal Mammography Quality Standards Act. Before that law, government investigations — and an NBC Nightly News expose — found that mammography centers were rife with barely trained staff, low-quality images, and equipment that exposed women to high radiation doses.
Today, with 39 million mammograms a year taken at 8,700 certified facilities, fewer than 1 percent of those sites have a serious violation of the regulations, according to the FDA, which posts the statistics online each month.
Of course, mammography remains controversial. On the X-ray, fatty tissue appears gray, while denser tissue, such as connective tissue or tumors, appears whiter. Many women, especially those with dense breasts, are called back for more imaging or even a biopsy because of ambiguous X-rays that turn out to be false alarms. Worse, studies suggest that some cancers that would never cause problems if left undetected wind up being treated.
However, studies also show that the latest technology — a three-dimensional mammogram called tomosynthesis — have improved detection while reducing false alarms.
So what is the rationale for using temperature variations to try to detect a malignancy?
Tumors spur the growth of blood vessels and speed up cellular metabolism, resulting in heat, explained surgical oncologist David H. Gorski, chief of breast surgery at Wayne State University School of Medicine in Detroit. In theory, mapping uneven heat patterns could flag problems.
But as Gorski pointed out in a blog post in Science-Based Medicine, the accuracy of the technology is unclear, there are no standards for performing and interpreting thermograms, and a proven technology — breast MRI — provides better metabolic information. MRI is recommended, and covered by insurance, as a complement to mammography for women at high risk of breast cancer.
Local physician Andrew Lipton is among those who believe thermography is valuable.
He offers it for the breast, as well as the whole body, at his Narberth family medicine practice. He has never gotten an FDA warning letter, but his website claims digital infrared imaging "detects changes due to breast cancer up to eight years prior to a mammogram." It also says "mammography can be ineffective" for younger women with dense breasts, and thermography offers "effective and sufficient results."
"Women looking for this or googling it are looking for an alternative to mammograms," said Lipton, who charges $600 for a full set of thermograms of both breasts.
Why doesn't he point out that the FDA says thermograms are not an alternative?
"I understand that some of the concern of the FDA is that women will avoid what's recommended. But they are already avoiding it," Lipton said. "I've never been warned by the FDA because I use [thermography] as a precursor, an adjunct. Often, we will send them for a mammogram" depending on what the thermogram shows.