WA News Letters MBI for breast screening
MBI for breast screening
Written by Ms Rhonda Harrup
Wednesday, 07 June 2017

 

Dear Editor,

For those not familiar with Molecular Breast Imaging (MBI) mentioned by Dr Liz Wylie (Dense breasts and mammograms, May edition), it is an emerging technology new to Australia. The first MBI camera is now operating in WA, the only state in Australia where the BreastScreen program discloses breast density composition to its patients.

MBI is a high resolution functional imaging technique developed at the Mayo Clinic in response to the requirement for a more effective secondary screening technique in women with dense breast tissue.

MBI employs the common radiotracer 99mTc-Sestamibi, which is also used for myocardial perfusion imaging. Two standard views are acquired for each breast in the same projections as mammography. Each view is acquired for around 8-10 minutes with the patient seated.

Unlike mammography, MBI does not require compression, merely immobilisation of the breast between the dual gamma detectors. The effective whole body radiation dose from MBI is approximately 2mSv, which is comparable to the level of annual natural background radiation in Australia.

US studies have shown that the addition of MBI to a screening mammogram leads to the detection of almost four times more cancers than conventional mammography alone in women with dense breast tissue.

The high specificity of MBI also leads to a reduction in the number of unnecessary (negative) biopsies compared to other secondary screening modalities and generates a cost saving of around 15% per cancer detected.

MBI is now used routinely for secondary screening in women with dense breast tissue at all Mayo Clinic sites, along with several other breast imaging centres throughout the US and Asia.

Ms Rhonda Harrup, Nuclear Medicine Technologist, Perth