from the ERA of Hope meeting I attended--new molecular imaging as accurate, less

[Lani]

costly than MRI

Research presented at the Department of Defense's annual Era of Hope breast cancer meeting indicates that molecular breast imaging (MBI) appears to have comparable sensitivity and specificity to magnetic resonance imaging (MRI) in the detection of breast cancers, but is more cost-effective.

The findings were reported by Dr. Carrie Beth Hruska of the Mayo Clinic in Rochester, Minnesota.

She and her colleagues performed MBI and MRI in 48 women being evaluated for breast cancer, 42 of whom had suspicious areas on previous examination and 6 who were at high risk for breast cancer. A total of 54 cancers were diagnosed in 32 patients.

There were 53 cancers detected by MRI in 31 patients, for a sensitivity of 98%. MBI revealed 51 cancers in 30 patients, for a sensitivity of 94%. One cancer was not detectable on MRI, MBI, mammography or ultrasound.

Sixteen patients were negative for cancer after MRI and MBI. There were nine true negative findings on MRI for a specificity of 56%. Eight were true negative on MBI for a specificity of 50%.

Because the majority of patients in this study had a high suspicion of having breast cancer, this specificity may not necessarily reflect that of a true screening population, Dr. Hruska cautioned.

"The MRI and MBI interpretations were concordant for presence of disease in 47 of the 48 patients," Dr. Hruska reported. In the case with discordance, two cancers detected on MRI were not detected by MBI.

"This was a retrospective look at patients who were not served well by mammography," Dr. Hruska commented in an interview with Reuters Health after her meeting presentation.

"The sensitivity and specificity of MBI were comparable with MRI," she said. "As MRI is being used more and more, cost will become a major factor. MBI costs four-to-six times less than MRI."

One important advantage of MBI over mammography is that it uses only light compression of the breast tissue rather than heavy compression, she continued.

"MBI is available only at the Mayo Clinic right now, but it will become more widely available soon," Dr. Hruska said. "MBI uses Tc99, which is used commonly in cardiac perfusion studies. It has a high affinity for cancer cells."

The technology still needs to be improved and larger studies are needed, but this is a promising, cost-effective method that may be useful for screening of breast cancer, she concluded.

[Jean]

Do you know of or have any research data on the Dilon
test?

http://www.dilon.com/

I was wondering if you have any stats with this test
compared to MRI..I did have the Dilon test done last
Nov. found it to be much cheaper $500 than MRI
easier to do/no pressure on the breast, and test
results are given by the time you are dressed.

I am wondering how it compares to MRI.

Thank you Lani,
Jean

[Lani]

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.

[Jean]

Lani,
As always thank you for the updated and accurate information.

I am a little miffed - where I go for my digital mammograms (she is an excellant dr.) but does not have the new Dilon machine, she told me the MRI
was better and more accurate than the Dilon. She was also
performing my MRI's every other 6 months. I had to wonder if she was advising me against the Dilon and in favor of MRI becausse she does not have the Dilon
machine.
Jean