FDA approval process slows efforts to bring CR mammography to U.S.

Fuji executives shoot for commercial release late this year

Plans to release a CR mammography system into the U.S. market this spring have stalled as the requisite premarket approval process slowed to a crawl at the FDA and set Fujifilm Medical USA months behind its schedule for commercial launch of the product.

Fuji intended to submit clinical data to the agency last October as part of a modular PMA submission. But the company continues to hold onto the results of clinical trials while the FDA refines its approach to approval of new mammography systems.

The FDA's review of CR mammography looks familiar to observers of its changing view of mammography-optimized printers, said John Strauss, director of marketing for Fujifilm Medical Systems. Originally, the only printers approved for digital mammography were those that had been submitted to the FDA by holders of PMAs for full-field digital mammography systems: Fischer, GE, and Hologic. Applications for subsequent printers had to be made as PMA supplements, which was an onerous process. The FDA later revised its stance and first allowed printers to be submitted as 510k applications with clinical data, later dropping the clinical data requirement.

"We have run into similar instances with the way FDA is reviewing CR mammography, and working through those changes has caused delays," Strauss said.

Last summer, executives at the company predicted that if clinical data were in FDA review last fall, CR for breast imaging would be on the U.S. market by April 2004. They are now forecasting a late 2004 release. Whether Fuji can meet that revised deadline, however, is anything but certain.

"We believe we have at this point an understanding with the FDA that will allow us to move forward," Strauss said. "We will be going very aggressively, when we do get approval, to share this technology with the U.S. marketplace. Our hope is that the approval process will be over in the second half of the year."

Fuji executives anticipate that CR will have the same kind of success in mammography that it enjoys in general-purpose radiography, where the technology has taken off in recent years as a low-cost alternative to systems with digital detectors.

Once CR mammography is commercially released in the U.S., mammographers should be able to use existing screen-film mammography equipment, which will hold down the cost of going digital yet allow them to reap the benefits of doing so. Fuji plans to capitalize on CR's flexibility and cost-effectiveness not only as a transition from analog to digital technology, but as a long-term digital solution.

Fuji's end-to-end CR mammography solution is built around its ClearView-CS reader, which accepts a dual-sided imaging plate with a clear polyester base and can read information from both sides of the plate using a 50-micron laser to enhance image quality. ClearView-CS was launched commercially late last year for nonmammographic applications. A field upgrade to the ClearView-CS for mammography would be made available to installed sites, and factory units would be reconfigured for digital mammography, if and when the FDA approves the marketing of the system for this purpose, according to Strauss.

A specially designed Fuji CR mammography viewing station provides magnification, windowing and leveling, panning, and advanced image processing features such as dynamic range control, multi-objective frequency processing, and pattern enhancement processing for mammography. The company's fully digital computer-aided detection system has achieved a 93% true-positive rate for microcalcifications and a 90% rate for tumors, according to the company. With links to Fuji's synapse PACS, CR mammography also incorporates information management.

The introduction of ClearView-CS for breast imaging would mark the return of Fuji to CR mammography. The company was marketing CR mammography with a 100-micron capability in the early 1980s. The technology has not been available in this country for years, however, because Fuji had to pull that product off the market while the FDA examined the safety and effectiveness of full-field digital mammography. The next generation of CR mammography has since been introduced outside the U.S. by Fuji, which claims to have installed about 1500 such systems, most of them in Europe and Asia.

Fuji is not alone in developing CR mammography. Agfa is refining a similar product as part of its Embrace portfolio. Because the mammography version uses the same platform as its general radiography system, Agfa CR breast screening might be added to existing radiography applications, according to Ann Verbeeck, global manager for women's care solutions for the Agfa-Gevaert Group. Agfa has about 120 CR mammography installations in Europe, including France, Italy, Germany, Spain, and the U.K.

Agfa has not yet begun clinical trials of its CR product, which uses powder phosphor screens as imaging detectors. Those trials are expected to start, however, at multiple sites later this year as a prelude to developing a PMA submission. After gaining FDA approval, Agfa plans to launch CR mammography as the last piece in a line of mammography options: film, CR, and DR, said Pat Montgomery, Agfa's manager for women's care for North America.

Down the road in a second wave of technology after powder phosphor, Agfa expects to launch a needle crystalline detector for x-ray CR. Needle phosphor technology has the potential to improve image quality, as the needles act as light guides that reduce the spread of light in the phosphor layer.

The current powder phosphor-based Embrace CR system employs data and image management tools that link with PACS and integrate patient scheduling, reporting, and CAD. The company's multimodal workstation accommodates CR and DR mammography, ultrasound, and breast MRI, as well as images from general radiography.

"CR mammography appears to be an easy, cost-effective way to go digital and leverage the analog modality. The advantages are low investment, added throughput, and high workflow efficiency," Verbeeck said.

CR systems could ride a wave of rising demand for digital mammography. Vendors of full-field digital detector systems report increasing interest in their products, which could rise further with the release of positive findings from the American College of Radiology Information Network Digital Mammography Image Screening Trial (ACRIN-DMIST). Results from this trial could be released in early 2005.

ACRIN-DMIST, which has been comparing breast cancer detection rates of digital mammography versus conventional screen-film mammography in more than 49,500 women, could influence third-party payers to boost reimbursement rates for digital mammography, Strauss said. The downstream effect on breast imaging centers would be to justify the switch from analog to digital breast imaging.

"The proven market acceptance for CR mammography, as indicated by the rest of the world-plus its versatility and cost-effectiveness-make it a very attractive product," he said. "The expectation is very high that CR mammography is going to represent a significant share of the full-field digital mammography systems in use."

One of CR mammography's strengths is its cost-effectiveness. Users don't have to jettison current analog units or alter workflow. They simply substitute a CR plate for a film cassette without making any changes in the acquisition phase of the imaging process. And there's no need to worry about processing the film, according to Montgomery.

Small sites, such as those with three mammography rooms that perform between four and six exams an hour, could get by with one CR reader, which is a fraction of the cost of flat-panel systems, said Andy Vandergrift, Fuji's national program manager for women's health. Centers that do radiography as well as mammography could use CR mammography as a multitask device, reading plates from both modalities. Even large breast imaging centers with 10 to 12 exam rooms that already have one flat-panel unit can keep costs in check by opting for CR mammography rather than adding more flat-panel units.

"The cost of ownership is a huge differential between the CR full-field digital device and digital technology being offered by other vendors," Vandergrift said.