FDA proposes final regulations for Mammography Quality Standards Act

New rules do not guarantee boom in device sales

The Food and Drug Administration last month unveiled its proposedfinal regulations as required by the Mammography Quality StandardsAct (SCAN 12/15/93). The rules are intended to replace interimregulations in effect since October 1994 with requirements thatdetail the equipment specifications practitioners must meet tostay in business.

FDA officials believe that older equipment in the installedbase of mammography devices might have to be retrofitted or replacedif the new requirements go into effect. But that does not meanmammography vendors are guaranteed a boom in sales in the nearfuture.

The regulations, as proposed, would be phased in over a 10-yearperiod so as to cushion the economic blow to practitioners, accordingto Charles Gunzburg, health promotions officer in the divisionof mammography quality and radiation programs of the FDA's Centerfor Devices and Radiological Health.

"We were concerned about the cost (of implementing allthe requirements at once) and about the impact on accessibility,so we prioritized the requirements and came up with a three-stepphase-in plan," Gunzburg said.

The first step would go into effect one year after final publicationof the requirements; the second would be implemented five yearsafter final publication; the third 10 years after publication.

Phasing in the requirements would allow older equipment tobe replaced with updated systems at a pace in keeping with whatthe FDA believes is a normal life cycle for mammography equipment.

"We based our phase-in plan on what the industry toldus is the expected life span of mammography equipment," Gunzburgsaid. "In 10 years, everybody should have turned their equipmentover."

Regardless of the length of the phase-in, however, the regulationswill have some positive effect on the sale of mammography equipment.

"The specifics of the regulations in terms of the individualrules don't matter as much as the fact that there is forced compliancein the installed base by certain dates or deadlines," saidPhilip Tusa, vice president of the RX division at Siemens MedicalSystems in Iselin, NJ. "This is the first modality for whichthere will be forced compliance, and that means demand (for qualitysystems) necessarily has to increase."

The proposed final regulations regarding mammography equipmentwere published in the April 3 edition of the Federal Registerand replace interim rules issued after MQSA was passed. The newrules provide more specific guidance on the technical specificationsthe FDA will require of mammography devices to ensure that womenreceive high-quality mammography. Before MQSA, for example, equipmentwas used for mammography that was not specifically designed forthat purpose.

"In the past, accessories were sold that would allow somegeneral-purpose x-ray equipment to be used for mammography,"Gunzburg said. "Those units usually didn't do a good jobof mammography and we wanted to make sure that they were not pressedinto service."

If the proposed regulations are enacted, practitioners willalso have to meet specifications on more than a dozen equipmentparameters. According to the proposed regulations, all mammographydevices must be designed specifically for mammography and musthave:

• a breast compression device;
• automatic exposure control (AEC) capability;
• mAs readout following each exposure on devices in which mAs is automatically selected;
• selection of tube potentials between 22 and 34 kVp;
• a minimum source to image receptor distance (SID) of 55 cm; and
• system resolution of 11 line pairs/mm when the high contrast resolution bar pattern is oriented with the bars perpendicular to the anode-cathode axis, and 13 lp/mm when the bars are parallel to that axis.

In addition, by Oct. 1, 2000, all mammography systems musthave a light field that approximates the x-ray field to assistin patient positioning and to ensure that the radiographic fieldis unobstructed.

The regulations were developed largely on the basis of recommendationsoffered by equipment focus groups convened by the American Collegeof Radiology with the support of the Centers for Disease Controland Prevention. An FDA advisory committee and manufacturers ofmammography equipment also advised the FDA in developing the specifications.Equipment manufacturers were given an opportunity to comment onan early draft of the proposed requirements published in the FederalRegister.

The requirements released last month are still a long way frombecoming law, Gunzburg noted.

"What we have presented might not be final," he said."We will wait and see what kinds of comments we get, go throughone more distillation process, and hope to come up with a goodset of regulations."

The revised regulations will be discussed at meetings of theadvisory committee and reviewed by the FDA and the Office of Managementand Budget. If approved, the regulations will be published infinal form in the Federal Register, an event not likely to happenuntil the middle or even the end of next year.