Healthcare

A recent conclusion about detection ability of additional occult breast cancer lesions in women who already have biopsy-proven breast cancer said that Breast-Specific Gama Imaging (BSGI) which is also known as molecular breast imaging, appears to be comparable to Magnetic Resonance Imaging (MRI).

The led author, Racher Brem, MD, from the George Washington University Hospital in Washington, DC, as June issue of the Academic Radiology write, “our study demonstrates that the detection of occult foci of breast cancer with BSGI is comparable to that reported for MRI.”

In the BSGI who involved 159 women in that study found occult cancer in the same breast as the index lesion in 9 women (6%) and in the contralateral breast in 5 women (3%).

The author say that BSGI, which requires that patients receivea radiotracer injection to image physiologic changes potentially related to breast cancer, has a number of advantages over MRI.

They write in the BSGI, patients are seated during imaging make it comfortable than MRI and allows for ‘more rapid physician interpretation’ because the technology generates 4 to 10 images ‘compared with hundreds or more for breast MRI.’

With this findings, a radiology expert who not involved in the study agreed with the author about their comparison.

Kathryn Evers, MD, from Fox Chase Cancer Center in Philadelphia, Pennsylvania, said that adding that patient comfortis greatly improved with BSGI.
She said about BSGI, “patients hate MRIs. It is also much easier to interpret.”
nevertheless, Dr. Evers is currently not lobbying her administrators to purchase a BSGI camera for her department of diagnostic imaging.

According to Dr. Evers, this technology has a fairly high radiation dose for a diagnostic test.
She added, “if an imaging technology does not have a low radiation dose, then you have to be more cautious about using it for screening and for follow-up of a benign lesion. If they can get the radiation dose down, I’m a fan and I’b buy one in an instant.”

Dr. Evers said that currently, there is no standard of care on the use of imaging to see if additional occult breast cancer is present in the same breast as an index lesion or in the contralateral breast.

She observed, there is ongoing debate about the use of staging MRI, and weighing benefits and risks is complex. “Nobody has a good answer,” she said.

Nevertheless, Dr. Evers thinks that a stronger argument can be made for imaging the contralateral breast than the breast with the index lesion because many women will receive whole-breast radiation as part of treatment.

She said about both BSGI and MRI which have similar rates of finding an additional cancer in the opposite breast in women with breast cancer and the rate of detection, “the contralateral breast findings are more compelling to me. Three percent is very small number but a real number.”

Dr. Brem deferred questions about radiation to the manufacturer of the BSGI machine (Dilon Diagnostic – Newport News, Virginia) used in the study, but pointed out that there is a history of using the radiotracer technetium (99mTc) sestamibi in heart imaging.

She said, “I can tell you that this dose of 99mTc sestamibi has been used for cardiac imaging for over 25 years. Furthermore, we minimize the dose as much as possible.”

According to Doug Kieper, Vice president of science and technology at Dilon Diagnostic said that the radiation dose used in the study was 20 millicures (mCi), and that radiation dose is not a significant concern for diagnostic breast cancer patients.

However, he said the company is currently conducting a trial to evaluate lower doses of the radiotracer in breast cancer patients.

As pointing out that the current study was performed with a new-generation camera, he added, “in theory, we can reduce the dose to 8 to 10 mCi, based on the design of the new gamma cameras.”
However, he said the study used the higher dose because a lower non-FDA-approved dose would have required the study team to perform a risk analysis to meet a typical Investigational Review Board’s requirement.

Althoughj the author of the study didn’t provide any information in the published study about the radiotracer dose used, Dr.Brem sees the importance of BSGI increasing.

She said, “I believe that BSGI will be adopted at many centers. It is important to realize that MRI and BSGI are not mutually exclusive imaging modalities.”
She added, “many women can’t have MRI because of limitations such as pacemakers, weight [restriction], or claustrophobia. Therefore, this expands out ability to diagnose breast cancer.”

According to Mr. Kieper, in the previous investigation, BSGI is seen as a potential complementary tool to mammography in screening women for breast cancer because it performs well in women with dense breast.
However, in this setting, he explained there are well-founded concerns about radiation dose because of the possible radiation risks associated with repeat screening.

He said, “in order for this modality to be used in annual screening in an asymptomatic population at standard risk for breast cancer, lower doses should be considered because of lifetime accumulative radiation dose.”