At the Food and Drug Administration, a small team of scientists is investigating how 3-D imaging — the technology used to create more realistic animations in video games and movies — could transform medical screening devices.
The scientists are focused on early breast cancer detection; in a process known as tomosynthesis, new screening machines take low-dose X-rays from various angles, overlaying them to produce a 3-D rendering of a patient’s breast. Traditional mammograms create a 2-D image, and cannot show cancers hidden by overlapping tissue, according to the FDA, which last week released a consumer update on the new technology to coincide with the start of Breast Cancer Awareness month.
Though 3-D screening machines are years from becoming commonplace in hospitals, FDA researchers say they are trying to keep up with an industry-wide transition from two- to three-dimensional imaging.
“Other industries are developing displays and fast computers that can be incorporated or utilized in [medical] images,” said Mary Pastel, deputy director for radiological health in the FDA’s office of in vitro diagnostics and radiological health. “The challenge for the FDA and industry is, at what point are those kinds of devices effective enough for the unique challenge of displaying medical images? Certainly Pixar images in movies can be moving toward quite realistic rendering, but there are substantial challenges displaying medical images with a very high pixel [rate].”
To date, the FDA has only approved two tomosynthesis systems for sale in the United States. General Electric’s SenoClaire, a software and hardware upgrade to GE’s older 2-D mammography system SenoGraph, won approval in late August. Hologic’s 3-D upgrade for its older systems was approved last year. (Both systems have had approval outside the United States for at least one year, according to the FDA.)
In the early stages of regulation and market approval, FDA physicists have tested each model’s hardware to ensure its screens can display images in high resolution and that images are clear and free of interference, among other elements. Technology companies hoping to sell tomosynthesis systems must also undergo a clinical trial process, providing the FDA with convincing evidence that 3-D systems detect more cases of early-stage breast cancer, relative to the radiation dosage in each scan, than their 2-D counterparts.
“Our ultimate goal is to develop a thorough enough [process] to shift our burden of evidence to the physics [of the device], and rely less and less on the requirement of a clinical study,” said Kyle Myers, director of the FDA’s division of imaging, diagnostics and software reliability.
Though FDA researchers continue to refine the approval process, some — such as the Allegheny Health Network in Pittsburgh — are eager to adopt 3-D imaging. The network, GE’s first customer for SenoClaire, is planning to purchase at least five tomosynthesis upgrades, to be installed in as many hospitals.
Allegheny Health Network is making an initial $1 million investment in these 3-D imaging systems, according to William Poller, director of breast imaging. Poller participated in GE’s study comparing results of 3-D screening to traditional 2-D mammography, and has been waiting until GE’s system secured FDA approval in the United States.
The network is “starting slow” when buying these units, Poller said, explaining that doctors and patients are still learning about the technology. In preparation, the network’s equipment service staff and IT department are being trained on how to maintain the new scanning systems. It has also invested in software and data storage to manage the influx of high-resolution images.
Once the first group of new systems are installed, Poller said radiologists will have to decide which patients will get to use the limited number of screening stations first — likely those with denser breasts, a family history of breast cancer, or other risk-factors.
He added, “of course, if a woman says, ‘I want tomosynthesis,’ [that’s] what we’re going to do.”