Based on a new study, a recent mammography process developed at the Paul Scherrer Institute (PSI), in collaboration with the Certified Breast Centre of the Kantonsspital Baden and the industrial partner Philips, could produce added value for the diagnosis of breast cancer in clinical practice.
The pioneering mammography procedure is rooted in the fact that as X-rays move through tissue, not only are they absorbed, but refracted. This supplemental information on refraction allows for a clearer, more detail oriented image of the breast and makes the smallest tissue changes visible.
For this study, international breast experts drew comparisons between conventional mammograms of recently resected breast tissue to images generated using the new method, leading to positive results. According to the authors of the study, the new image quality not only delivers a more accurate diagnosis of breast cancer, but it could also significantly improve early detection.
The study, which has been published in the journal Investigative Radiology, assessed the imaging quality and the possible clinical significance of the new methodology. To this end, experienced radiologists compared the quality of standard mammograms with those of the novel method. Assessing the breast tissue of 33 patients who had recently undergone surgery, the experts concurred that the new images were of far better and higher quality than normal mammogram images. Therefore, such a technique could amount to a great advancement for the diagnosis of breast cancer.
When employing the new technique, the demarcation between tumor tissue and healthy tissue is better distinguished. Even the fine extensions of the growth are clearly recognizable.
“This may mean it is possible to better prepare for an operation and to determine the surgical area more accurately. Small white flecks are also visible in the images. These microcalcifications provide information about the malignancy of changes in breast tissue depending on their sizes and structures,” said Director of the Certified Breast Centre at the Kantonsspital Baden, Nik Hauser.
“As the increased image sharpness already makes many smaller structures of this kind visible, breast cancer could also be detected at a very early pre-stage. “This is extremely promising in practice,” says Hauser, since “the earlier we detect and treat a suspicious change in tissue, the greater the chances of survival,” he added.
In traditional mammography, one measures how much of the radiation passes through the breast tissue and how much is maintained. This ratio harps on the nature of the tissue, and usually shows little to no differences making identifying between tumors and healthy tissue very difficult. However, when X-rays pass through tissue, they are not only attenuated but also slightly customized in their direction. This additional information can be regained in the images produced by the new technique and significantly adds to increasing contrast and feature description in the new mammograms. PSI has been promoting and encouraging this method for several years.
“Instead of just measuring their absorption, we worked out how to record the refraction and scattering of the x-rays as well. Another advantage is that these significantly improved images can theoretically be obtained with the same x-ray dose as with the conventional mammogram. We are working very hard on this aspect, since this is crucial for the implementation of our approach into clinical devices,” notes leader of the project at PSI and professor at the ETH Zurich, Marco Stampanoni.
Securing a small dose is essential because the X-ray exposure of the body must be kept to a minimum. Therefore, in order to introduce and apply this method in practice, studies in patients must compare the innovative method with the standard method used today.
Thereby, in a next study, patients with a previously diagnosed malignant breast tumor will be examined again with a mammogram obtained with the new method. For those patients, the enhanced images could potentially improve the succeeding treatment.
“We have already covered a significant part of the road towards the implementation of the new technology in practice– we’re on the home stretch now. As a next step, we want to validate the new mammography procedure in patients,” said Stampanoni.
As of now, the team has high expectations of the first tests using this innovative method; and are confident this advancement will become a routine part of medical practice.
“Once it is available, it will quickly gain acceptance,” said Hauser.
