Once Wilhelm Conrad Röntgen had discovered X-rays in November 1895, physicians everywhere began researching with the rays that would change the world. One of their hopes was that X-rays would allow them to see cancer at an earlier stage.
The first attempts to produce X-ray images capable of displaying pathological changes in the mammary glands also began in these early years of what would later become radiology. Physicians working at the end of the 19th century could only detect breast cancer in the later stages. By that point, the disease was usually so far advanced that operating was of no help to the patient. As a result, physicians and scientists were very interested in using the newly evolving technology to detect breast cancer early and thereby help many women.
In those early days, the German surgeon Albert Salomon was among those to focus on examining the female breast. He was the first to detect breast cancer using X-rays. He conducted his first experiments on 3,000 surgical specimens taken from the breast. These he X-rayed and then dissected. Without ever experimenting on a living person, Salomon developed a method that made it possible to “reliably” – by the standards of the day – differentiate between benign and malignant tissue on an X-ray image. The X-ray images also led Salomon to discover that there were different types of breast cancer. When he published his research findings in 1913, other physicians were hesitant to adopt his method, despite the impressive results. Today, he is considered the founder of breast radiology – better known as mammography.1
More research into mammography was carried out from the 1920s – primarily in Germany, South America, France, and the US. The world’s first clinical mammography was performed in 1927 by the surgeon Otto Kleinschmidt at Leipzig University Hospital.2
Large-scale studies carried out with thousands of women in the 1950s showed the high quality of mammography results. With so many women suffering from breast cancer worldwide, the need for better breast cancer diagnosis was more urgent than ever. One of the hospitals that paid particular attention to the field was Heidelberg University Women’s Hospital. From 1957, it conducted systematic breast examinations using a Siemens Tridoros 4 X-ray generator equipped with special mammocones. In 1962, Dietrich Buttenberg, MD, used the results as the basis for the first mammography reference book to be published in Germany: Die Mammographie.3
In the following years, many physicians and scientists worked on improving the examination method further. One of them was Professor Walter Dobretsberger, MD, who was based at Krankenhaus der Barmherzigen Brüder, a hospital in Linz, Austria. He developed the isodense technique (also known as fluidography), an examination method that involved submerging the breast in alcohol while the patient lay on a special apparatus. The advantage of this method was that the specific weight of alcohol is largely the same as that of breast tissue, which resulted in a better X-ray image than was previously possible. A company in Vienna, Siemens-Reiniger-Werke GmbH, named the device the Fluidograph and launched it in 1964.
In addition to the technological developments, it soon became clear that radiologists needed special training to be able to interpret X-ray images of the breast correctly. The first mammography training program for physicians was therefore developed around 1960. In addition, researchers in the 1960s and 70s were already working on ways of reducing radiation dose.
In 1972, Siemens presented its first “real” mammography system (as we know it today) designed specifically for the female breast. A brochure described the Mammomat, somewhat awkwardly, as “a workplace unit for radiological mammary diagnostics.”
The next generation followed in the 1980s. The systems became faster and easier to use. Patient-friendlier systems and, as far as possible, a “more pleasant” examination were becoming increasingly important factors. In 1994, for instance, a press release introducing the Mammomat 3000 said it allowed women to “breathe easy.” The device featured an automated compression system which reduced the pressure on the patient’s breast. At that stage, all mammography systems were analog; the first digital systems arrived in the early 2000s. In the following years, developers worked on further refining the technology. Special programs, for instance, were developed to help physicians evaluate X-ray images with computer-aided detection. One of the latest mammography technologies is digital breast tomosynthesis, which produces three-dimensional images of the breast in slices. This makes it possible to view the tissue without any overlapping, which provides physicians with even more accurate information for their diagnosis and reduces the number of false-positives. Physicist Thomas Mertelmeier, who works at Siemens Healthineers in Erlangen, received the 2009 Siemens Inventor of the Year award in recognition of his research on developing digital 2D mammography into 3D tomosynthesis.
The Early Days of Mammography Screening
Many countries, including Sweden, the UK, and Canada, introduced mammography screening in the 1980s for healthy women once they reached a certain age. Breast cancer screening only became established in Germany in 2003. Siemens mammography systems have also been installed in special trucks. In 2006, they began traveling across Germany as part of the country’s Mammo-Screening project. This kind of mobile digital breast cancer screening is designed to reach women who live in rural areas, or those are no longer as mobile as they once were.