Computed radiography for mammography cannot yet be sold in the U.S., but mammographers elsewhere in the world have been able to buy it from Agfa Healthcare. Many of those who bought this technology, called the Embrace CR (1A), probably wish they hadn’t.
Computed radiography for mammography cannot yet be sold in the U.S., but mammographers elsewhere in the world have been able to buy it from Agfa Healthcare. Many of those who bought this technology, called the Embrace CR (1A), probably wish they hadn't.
Mounting concerns about the product's inability to visualize microcalcifications led Agfa to stop selling the product in May and recall those installed at clinical sites around the world. The company is now preparing to launch an upgraded CR mammography solution, called the CR Mammo (1B). This system matches the performance of screen-film systems in detecting microcalcifications, according to the company, thereby eliminating the root cause of the recall.
The shortcomings of the unit did not surprise company executives nor should they have surprised customers, according to Iskander Accaoui, Agfa's digital radiography global marketing manager. Customers purchasing the Embrace CR (1A) were advised upfront that they might have difficulty spotting microcalcifications in very dense breast tissue.
"This was an identified limitation of the system," Accaoui said.
The system's weakness in detecting microcalcifications meant that it was marketed solely for diagnostic mammography, which involves the imaging of a primarily symptomatic population who will likely receive regular, repeat examination. Embrace CR (1A) was not, in fact, approved for population-based breast screening, in which the majority of images generated contain no abnormalities, and the time period between scans is longer.
A customer complaint in December 2003, however, prompted Agfa to reassess its system's fitness for mammographic application. The objection was raised by a radiologist working in France, who observed that "powder" microcalcifications could not be seen on a patient's CR mammogram. The dusty abnormalities could be observed quite clearly on screen-film images.
"This did not lead to a misdiagnosis because the patient had presented for a follow-up scan after a biopsy," Accaoui said.
French investigators recognized that mammography equipment, regardless of its sophistication or type, could not reveal difficult-to-image microcalcifications in 100% of cases. But they took issue with the way Agfa "alerted" prospective patients to its system's potential shortcomings.
They noted that problems visualizing abnormalities in breast tissue may become apparent only after diagnostic imaging. If CR is used as standard, patients with dense breasts are likely to need a repeat scan on a screen-film system. Consequently, these patients would receive a double dose of ionizing radiation, a prospect that French investigators found unacceptable.
The investigators informed Agfa in May 2004 that such a protocol would breach European legislation, which dictates that patients should not undergo unnecessary medical x-ray exams, Accaoui said. Agfa agreed and asked all Embrace CR (1A) users to stop using the system immediately.
A few of these customers are in Asia and Latin America. Most of the 60 Embrace CR (1A) systems, however, were shipped to European radiology departments and breast clinics. Agfa is now preparing to upgrade those sites to its CR Mammo (1B) solution, which includes new phosphor plates and a new CR digitizer.
The upgraded system produces images clinically documented to match the quality of those produced by screen-film equipment for diagnostic mammography, Accaoui said. If ready, it will be shown at this month's annual meeting of the French national radiological society in Paris. Delegates at the upcoming RSNA meeting will also get to view the upgraded CR solution, though no orders can be taken from U.S. institutions pending FDA approval.
"We need to provide answers to the 60 sites that were using our CR mammography," Accaoui said. "This is where we are going to explain the situation to them in more detail."
He is hopeful that the reported problems and temporary withdrawal of Agfa CR equipment for mammography has no long-term effect on customer confidence in Agfa CR.
"We took this measure to ensure safety, and we hope that customers will appreciate we were taking all necessary precautions," he said. "Of course, it was a disturbance to them because they had to stop working for months, but I think they have been very understanding."