FDA hears debate on digital mammo status

Testimony heard by a Food and Drug Administration medical device committee on March 6 encouragedoptimism among advocates of full-field-of-view digital mammographywho fear the FDA will delay the new technology`s introductionin the U.S. market.

The advisory committee, chaired by Dr. Francine Halberg, convenedto solicit guidance on the FDA's proposal to regulate the full-viewdigital breast imagers as class-three devices. The designationwould require that manufacturers submit premarket approval applications(PMAs) in order to sell the devices in the U.S. (SCAN 1/18/95).

Unlike the 510(k) equivalency process that pertains to makersof film-based mammography systems, PMAs require original clinicalresearch to demonstrate efficacy and safety. FDA 510(k) clearanceusually take a few months, while PMAs often take several yearsbefore the agency rules on the application.

"The industry's position is that a 510(k) will suffice,and we came away from that meeting feeling that's the directionthe panel is leaning toward as well," said Vicki Schofield,industry manager of the National Electrical Manufacturers Association,the equipment vendors' trade group.

Panelists identified a need for additional study, but concludedthat the intensive field research typically undertaken for a PMAis not essential, Schofield said.

Included among several proposals was a plan to limit the initialclinical use of full-view digital mammography to diagnostic breastimaging, Schofield said. Regulatory approval for screening applicationscould come after clinical testing has been reviewed.

"The type of research discussed seemed reasonable,"Schofield said. "Population sizes for these studies shouldbe in the hundreds of patients, not the thousands. The time frameis measured in months, not in years."

An exact accounting of what the discussion means will cometo light when the FDA publishes a proposed protocol for publiccomment in the Federal Register, Schofield said. A timetable forthat step has not be disclosed, but a decision is expected soon,according to the FDA.