Data submitted by Hologic to the FDA panel suggested the combination testing offered twice the level of radiation as conventional mammography alone.
And, while the studies submitted to the FDA suggested a reduced rate of follow-up screenings in women, the studies offered no indication that the combination of tests could detect breast cancer not picked up by conventional mammograms.
"There still needs to be additional work to keep the radiation dose of screening studies very low and figure out which women will most benefit from this new technology," said Conant.
The panel subsequently sent Hologic a so-called approvable letter, subjecting the company to manufacturing inspections before final approval.
Hologic refused to offer a timeframe for approval but Jim Culley, Hologic's director of marketing told ABCNews.com he's confident of approval, since the company has been manufacturing and selling the device to other countries for the past two years.
Indeed, tomosynthesis may offer better imaging for breast cancer detection than seemingly older technologies, but many experts said until it proves better than the current digital mammogram available, it may be a hard sell.
"Without stronger evidence, [tomosynthesis] will not become widely available to patients," said Dr. Etta Driscoll Pisano, chief of breast imaging and dean of the University of South Carolina College of Medicine. "It is likely to reduce false positives. It may find more cancers, but maybe not.
"I hope the comparative effectiveness studies are done to figure it out," she said.