The multi-modality approach to the diagnosis, treatment and rehabilitation of breast diseases (senology) is becoming more popular among physicians. Imaging techniques such as ultrasound and 3D breast tomosynthesis play an increasingly significant role – from early detection and diagnostics to after-care for breast cancer patients. These new technologies provide improved image quality and optimized workflows which support the physician during the examination.
Digital mammography for screening
The digital full-field system Mammomat Inspiration with its basic function for screening has been on the market since the end of 2007. Presently, it has been implemented in more than 500 hospitals and private practices worldwide. Many new components provide physicians with improved images of the patient’s breasts facilitating diagnostic activities. The system features a MoodLight function, which makes the examination environment more comfortable and less stressful for the patient. A host of functions and technical details allow for less radiation exposure during the examination than previously by using, e.g., a special X-ray tube with a Tungsten anode or new AEC algorithms,2 which calculate individual doses depending on the size and tissue characteristics of the breast. With the Mammomat Inspiration, physicians can perform biopsies in a simple and automated way with an additional biopsy unit that slides onto the mammography platform by hand. The mammography system automatically detects the biopsy unit and converts all functions of the hardware and software for the biopsy mode.
Tomosynthesis is a new mammography technique that expands conventional 2D mammography into an imaging technique similar to computed tomography generating 3D exposures of the breast. Taking exposures from several angles, a software-based algorithm uses the projection images to calculate 3D images without overlapping tissue, providing the radiologist with improved information. To date, Siemens has sold around 50 breast tomosynthesis systems worldwide.
Ultrasound for early breast cancer detection
In cases of dense breast tissue or ambiguous mammography findings, ultrasound is widely used as an additional imaging modality to support physicians in reaching a more informed diagnosis. According to the New England Journal of Medicine3 , dense breast tissue increases the risk of breast cancer by a factor of five. While conventional mammography is the method of choice for early breast cancer detection, a study published by the RSNA (Radiological Society of North America) in 20084 found that if a screening ultrasound was added to a routine mammogram, 20 percent more cancers were revealed than with mammography alone.
Operator dependency and the time needed for hand held ultrasound have restricted its role in breast imaging to that of a secondary imaging modality to look at a palpable mass or a finding identified on a mammogram. A new method of acquiring and analyzing ultrasound images has the potential to change that. The ACUSON S2000 Automated Breast Volume Scanner (ABVS) from Siemens is the world’s first multi-functional ultrasound breast scanner to automatically acquire full volumes of the breast. The system not only allows full-field volumetric image acquisition in less than 10 minutes, the sonographic volumes also provide an improved overview of the anatomy and architecture of the breast. Providing not only offline transverse and sagittal reconstructions, the ACUSON S2000 ABVS also allows the display of the unique anatomical coronal view – from the nipple to the breast wall – which to date has not been available with conventional ultrasound imaging. This coronal view accelerates the diagnostic process and is a valuable instrument in operation rooms and resection planning. The ACUSON S2000 ABVS is especially suitable for the early detection of breast cancer in women with dense breast tissue and highly suitable for the aftercare of breast cancer patients.
Increasingly promising for the examinations of nodes or changes in tissue (lesions) that are indicative of malignant changes is the relatively new method of elastography in breast imaging. Elastography provides physicians with a higher level of accuracy when characterizing breast lesions. Using soft tissue compression, eSie Touch elasticity imaging forms an elastogram that assesses the mechanical properties, or stiffness of tissue which is often correlated with pathology. According to the American Cancer Society, 80 percent of all biopsied breast lesions are benign, which is why a reduction of the number of unnecessary invasive breast biopsies would be highly welcome.
Some other diagnostic technologies introduced by Siemens and used abroad are:
Innovations in magnetic resonance imaging (MRI) for breast imaging
Siemens developed the MRI system Magnetom Espree - Pink especially for breast imaging. The large magnet aperture of 70 cm makes examinations more comfortable, particularly for obese or claustrophobic patients than previous systems. For patients who felt cramped in previous systems, the design of the Magnetom Espree - Pink is highly advantageous. A so-called coil can be adjusted to different breast sizes and delivers excellent diagnostic image quality. In addition, biopsies can be performed with this MR breast scanner, should they become necessary.
Molecular imaging in breast cancer diagnosis
Siemens offers applications of various molecular imaging procedures for the diagnosis and therapy of breast cancer. Lymphatic drainage scintigraphy using the Symbia SPECT/CT system (Single Photon Emissions Computed Tomography / Computed Tomography) enables the tracking of sentinel lymph nodes using radioactively marked substances that concentrate in them. Precise localization of these lymph nodes is possible even in complex locations because the anatomic landmarks can be displayed in a CT scan. Laboratory examination of these sentinel lymph nodes can eliminate the need to remove all axillary lymph nodes and the resulting complications, for many patients.
The newest system from Siemens – the Biograph mCT molecular computed tomography system – helps in providing a precise cancer diagnosis. The system can be used in both radiology and nuclear medicine and is suited for PET/CT (Positron Emissions Tomography) as well as pure CT examinations. Various biomarkers help here in localizing remote metastases in bones and other tissue, supporting the physician in more precisely planning the follow-up therapy.
Advances in radiation therapy providing individualized treatment
For clinicians, treating breast cancer presents a number of challenges and care must be taken to spare healthy tissue; particularly the contralateral breast tissue, as well as the heart and lungs. Siemens’ latest linear accelerator, Artiste Solution, conveniently integrates imaging and treatment delivery technologies into one machine, giving clinicians the flexibility to provide specialized care. One of the imaging options, MVision Cone Beam Imaging, is efficient at providing the sharp soft-tissue contrast needed to precisely position the breast cancer patient. Using the 3D images acquired with MVision and Artiste’s 160 MLC Multileaf Collimator’s fast leaf speed allow clinicians to quickly and accurately deliver higher radiation doses to the target while helping to protect surrounding healthy tissue and vital organs.
1 As per a study conducted by the International Agency for Research on Cancer (IARC); http://www.thaindian.com/newsportal/health1/womens-car-rally-to-create-breast-cancer-awareness_100335494.html
2 AEC=Adaptive Exposure Correction; A new AEC algorithm further optimized dose calculation. All exposure parameters are adjusted automatically to the size and structure of the breast. Adaptive AEC offers significant flexibility in positioning the breast.
3 N Engl J Med 356;3. Boyd N.F. et Al., Mammographic Density and the Risk and Detection of Breast Cancer
4 JAMA, May 14; 299: 2151 - 2163
Siemens Healthcare Sector
is one of the world's largest suppliers to the healthcare industry and a trendsetter in medical imaging, laboratory diagnostics, medical information technology and hearing aids. Siemens offers its customers products and solutions for the entire range of patient care from a single source – from prevention and early detection to diagnosis, and on to treatment and aftercare. By optimizing clinical workflows for the most common diseases, Siemens also makes healthcare faster, better and more cost-effective. Siemens Healthcare employs some 48,000 employees worldwide and operates around the world. In fiscal year 2009 (to September 30), the Sector posted revenue of 11.9 billion euros and profit of around 1.5 billion euros. For further information please visit: www.siemens.com/healthcare