New 3D CT technique could diagnose breast cancer earlier
Scientists from Finland, Germany and the European Synchrotron Radiation Facility (ESRF) have developed analyzer-based x-ray imaging (ABI), a new CT technique used for the early detection of breast cancer.

X-ray mammography fails to identify about 10 to 20 percent of palpable breast cancers. This is because some breasts, despite widespread use. While better results are obtained using x-ray CT, its use in breast imaging is limited by the radiation dose delivered to a radiosensitive organ such as the breast, according to the researchers.

A new CT technique has allowed scientists to overcome the problem. The teams from the Helsinki University Central Hospital, Turku University Central Hospital (Finland), the Radiation and Nuclear Safety Authority (Finland), the University Hospital of Grenoble (France), the European Molecular Biology Laboratory in Hamburg (Germany) and the Biomedical experimental station (beamline) at the ESRF have managed to visualize breast cancer with an unprecedented contrast resolution and with clinically compatible doses.

The researchers, including physicists, surgeons, radiologists and pathologists, used ABI on an in vitro specimen at the ESRF, using a radiation dose similar to that of a mammography examination. The team found that dose corresponded to a quarter of that required for imaging the same sample with conventional CT scanner, and the spatial resolution of the ABI images was seven times better.

For the experiment, researchers chose a breast that had a lobular carcinoma, the second most common form of breast cancer, which is also very difficult to visualize in clinical mammography. In this sample, the determination of the extension of the cancer frequently fails in x-ray mammograms and ultrasonographs of the breast.

The results showed that high-spatial-resolution ABI-CT makes visible small-size and low-contrast anatomic details that could otherwise only be seen by the microscopic study of an extracted sample of the breast tissue, according to the researchers.

"We can clearly distinguish more microcalcifications…than with radiography methods and improve the definition of their shapes and margins,” explained Jani Keyriläinen, the study’s main author. "If we compare the images with x-ray mammograms and conventional CT images, we can confirm that this technique performs extremely well.”

Despite having studied only in vitro samples, the team is very optimistic that the technique will be applied in the future in clinics. "The technique does not require sophisticated and expensive synchrotron radiation facilities,” said Alberto Bravin, chief scientist of the biomedical beamline at the ESRF. However, "it would not be viable to use x-ray tubes, as exposure times would be too long and this would be incompatible with clinical practice.”

The scientists said that they hope that current worldwide development of compact, highly intense x-ray sources will enable the clinical use of the technique. Once it has been confirmed and tabletop synchrotrons are on the market, the progression could be very straightforward, according to the authors.