FDA Panel Endorses New Breast Cancer Screening Option

Fran Lowry

October 25, 2012

The US Food and Drug Administration's (FDA's) Radiological Devices Panel of the Medical Devices Advisory Committee has voted 9 to 1 to endorse the Selenia Dimensions 3-D System With C-View Software Module (Hologic Inc) as a new option for breast cancer screening, calling it safe and effective, with a favorable risk-benefit ratio.

The system was approved by the FDA in 2011 for breast cancer screening and diagnosis. Screening can consist of field digital mammography (FFDM) alone or a combination of FFDM and digital breast tomosynthesis (DBT).

The new element being recommended for approval is that the addition of the software module can generate synthetic 2-dimensional images from the DBT data, thus obviating the need for acquiring standard FFDM images.

Hologic was asking the FDA to allow the combination of DBT with synthetic 2-dimensaional images to be used as another exam option for screening women for breast cancer.

Before voting, the panel discussed a number of questions for the FDA, including aspects of performing and interpreting mammography that should be included in the training and labeling when traditional FFDM images are not acquired during the screening exam.

The consensus of the panel was that there will need to be specific training not just for radiologists and technologists but also for physicists, so that they can use the system optimally.

"There will be issues related to use of C-view by radiologists outside the facility that has C-view," Robert D. Rosenberg, MD, from Associates of Albuquerque in New Mexico, and chair of the Radiological Devices Medical Advisory Panel, said. "This is not an impediment to the use of the new technology, but it represents a significant training issue and a labeling issue."

In the studies it presented to the FDA, Hologic excluded women with large breasts, surgical or excisional biopsies, and breast implants.

For Robert M. Faulk, MD, from Medical Imaging Consultants in Omaha, Nebraska, this was a serious fault and a cause for him to cast the only "no" vote.

"The study was performed with all of these exclusions. I don't think we can be certain that the results are transferrable to the general population," he said. "The exclusions amount to about 30% of the general population, and I have a lot of uncertainty that the results can be generalized to women in general."

Dr. Faulk added that many of the women he sees in his local practice would have been excluded from Hologic's study. "My question to the FDA is, What proof do they have that the results of this study are transferrable to the general population?"

Elizabeth A. Rafferty, MD, from Massachusetts General Hospital in Boston, who presented on behalf of Hologic, countered that the 3-dimensional system plus C-view was superior to 2-dimensional FFDM largely because of the tomosynthesis element.

"This is an important option for those particular women, because the radiation dose is decreased with C-view," she said.

Regina J. Hooley, MD, from Yale University School of Medicine in New Haven, Connecticut, did not believe that large-breasted women would pose a problem with C-view. "I don't see that as being a worrisome exclusion, nor do I see women with implants as being a worrisome exclusion. Implant cases are always difficult to read."

Douglas M. Coldwell, MD, PhD, from the University of Louisville in Kentucky, said that the excluded women could provide an incentive for researchers to perform a study on them, adding, "It seems almost superfluous to require studying this group as a postmarketing surveillance study. We know that these subgroups will be addressed, and the results published in future studies."

Consumer representative Carol A. Price, RN, from Susan G. Komen for the Cure, Cincinnati, Ohio, admitted she had mixed feelings about the new technology, even though she voted for its approval.

"As a breast cancer survivor, I don't want to see anyone left out, but I would also feel that Hologic has not covered all the bases. Also, very few centers are offering 3-D with C-view. How are physicians who refer their patients for mammography even going to know it exists?"

She was reassured by Justin P. Smith, MD, from Inland Imaging, PS, in Spokane, Washington.

"I live in a very competitive area and I can tell you that if...another hospital acquires a broom that is considered superior, the competitor hospital will get it in a heartbeat. So hospitals will advertise that they have this new technology," he said.

Meeting of the Radiological Devices Advisory Panel, Silver Spring, Maryland. Presented October 24, 2012.

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