View VideoThe Dilon 6800 Gamma Camera enables optimized molecular breast imaging with a high-resolution, small field-of-view detector for image acquisition. The Dilon 6800 overcomes the limitations of a standard gamma camera through a patented detector that produces high contrast images of significantly smaller lesions and helps practitioners determine the presence or absence of cancer. The detector's compact size allows imaging close to the chest wall and in all standard mammographic views for direct correlation to mammograms. An additional benefit is that patients are able to sit comfortably throughout the image acquisition process, rather than lie prone as with standard gamma cameras.
BSGI, as a functional or molecular procedure, images cellular activity while both MRI and Ultrasound image tissue density. Functional imaging allows physicians to see the breast more clearly by accessing a map of cellular metabolism. Certain types of breast tissue may interfere with cancer detection. The need for a complementary diagnostic procedure to mammography is filled by a test that provides for improved sensitivity and specificity such as BSGI.
Mammograms image tissue densities, not cancer activity. BSGI with the Dilon 6800 uses radiotracer uptake to detect cancer independent of tissue density.
With negative predictive values of 99%, and high sensitivity for lesions as small as 3 mm, BSGI with the Dilon 6800 has been integrated into the diagnostic protocol for challenging cases.
“In clinical studies lesions as small as 1mm have been reported by pathology- for both invasive cancer and DCIS. In addition, reports from studies and clinical practice demonstrate a high sensitivity for DCIS and lobular carcinoma.”
MRI has shown usefulness as a next-step imaging modality for difficult-to-diagnose cases. Much like x-ray mammography, breast MRI relies on anatomical or structural information, but provides much more detailed images. It is limited however, by its highly variable specificity, which can range from below 37% to 97%. Combined with its high sensitivity, MRI produces a high false positive rate, is an expensive test to administer, is often difficult to schedule and may require multiple days to complete.
The specificity of BSGI/scintimammography has historically been higher than that of breast MRI. In addition, Dr. Petrovitch presented data at the 2005 RSNA showing that in the same patient population BSGI had comparable sensitivity, but higher specificity than breast MRI (High Resolution Molecular Breast Imaging with 99m-MIBI and Magnetic Resonance Imaging in the Assessment of Breast Cancer, 2005). There are also several factors which limit the use of breast MRI in patients.
- First, not all patients can physically comply with an MRI order. Breast size, obesity and various medical implants are just a few of the factors that limit the use of MRI in this patient subset.
- Second, some insurance programs limit the use of breast MRI. This means that there is a large group of patients who could benefit from additional imaging, but are excluded from using MRI due to financial considerations. BSGI is an excellent alternative for both of these cases.
Ultrasound is also commonly utilized as a next-step after a questionable mammogram and is good at determining if a suspect mass is solid or fluid-filled. However, ultrasound demonstrates a low specificity that can produce misleading results and indicate biopsy where one may not be needed.
BSGI, as a functional procedure, images cellular activity while both MRI and Ultrasound image tissue density. Functional imaging allows physicians to see the breast more clearly by accessing a map of cellular metabolism. Certain types of breast tissue may interfere with cancer detection. The need for a complementary diagnostic procedure to mammography is filled by a test that provides for improved sensitivity and specificity such as BSGI.