MRI Breast Screenings and Biopsy

At a meeting with such a heavy emphasis on breast cancer, Debra Ikeda's talk offered some great information to put all of the new innovations into focus. While most of the speakers were medical physicists working at the cutting edge of technology, Ikeda is a professor of Radiology at Stanford and is working to better define a standard of care for breast MRI and MRI biopsy. So her view of the problem stems from a growing understanding of the biological nature of breast cancer and the problems that face doctors in the field. "I just want to say as a radiologist that I'm very excited to hear about what you guys are working on," Ikeda said to her fellow presenters.

Breast cancer originates near the root of the milk ducts in the breast, and cancerous cells can move from the ball-shaped root down the ducts.  This early form of breast cancer, known as ductal carcinoma in situ (DCIS), is very difficult to detect.  Later on the cancerous cells can break out of the ducts and become invasive, growing into more recognizable tumors.  While Ikeda promoted MRI treatment, she noted that traditional mammography is actually 25% more effective at identifying this early stage of breast cancer than MRI. 

Most breast cancer patients have their entire breast radiated after the removal of a tumor, to eliminate the risk of the cancer returning through the ducts. Because each breast has multiple ducts, there can be multiple cancer foci in the breast.

Typical tumors usually possess a very high amount of blood vessels. This is one easy to way to spot a tumor - by injecting the patient with a marker or angiogenesis drug, a tumor will uptake the injection faster than the rest of the breast because of the number of blood vessels (although this isn't always the case).

MRI is more effective than traditional mammography in identifying tumors, especially in high risk patients with dense breast tissue (Ikeda does note, however, that they should be used together, as they both have their advantages). One study of over seven hundred US practices showed that three quarters offer MRI for breast cancer screenings, although the majority of those only do about 5 a week (which is relatively low). 31% percent of those, however, do not do MRI biopsy, which Ikeda believes needs to change. A biopsy is an invasive process that takes tissue samples from an identified abnormality and identifies it as cancer or benign. "It's important to be able to biopsy when you see something abnormal," says Ikeda. "It would be horrible to be told 'You've got something...but we can't biopsy it.'" Ideally of course, methods would increase for discerning between benign lumps in the breast without the need for biopsy.

To more fully understand exactly what physicians will see on MRI scans of different patients, how to look for signs of early cancer, and what standard screening steps to take, Ikeda sits on the BIRAD Lexicon Committee, which constructs the yearly ACR Atlas. The Atlas will compile information to hopefully answer those questions, but it will rely on detailed information from physicians.

The committee's requests to radiologists include doing bilateral screening in patients (comparing both breasts), comparative studies among patients, and careful descriptions background enhancement.

Background enhancement describes how much of the dense tissue in the breast is enhancing; it's more of a change in the dense tissue rather than the volume of dense tissue. Background enhancement can change due to natural hormone cycles which can fool an MRI into looking like cancerous tissue Different types of background enhancement filters can better differentiate dense tissue fluctuations.

Four to five percent of women who develop breast cancer will develop it in both breasts, so Ikeda emphasizes the need for doctors to do bilateral care and report their findings. The bilateral studies also make it easier to identify abnormalities in each breast.

As I mentioned before, breast cancer imaging, screening, diagnosis and treatment were discussed in more sessions than perhaps any other topic on the IPF agenda. While the science was all fascinating, this session brought home the human aspect of all the research. It was held in memoriam of Carolyn Kimme-Smith, a leading radiologist in the field of breast cancer study who also suffered from breast cancer. Ikeda began her talk with a quick tribute of her own to Kimme-Smith, saying she was always kind to and respectful of other people, even when their ideas conflicted.