Radiology
Guidelines for
Referring a Patient for Breast MRI By Ashley Hawkins, M.D.
Currently, breast magnetic resonance imaging (MRI) is a staple in the armamentarium of today’s breast radiologist. Despite the increased broad clinical use of breast MRI, there is still some confusion among clinicians as to when to refer a patient for a breast MRI. This article intends to outline the current indications for breast MRI. They can be
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The Triangle Physician
divided into three broad categories: implant integrity, breast cancer screening and new diagnosis of breast cancer.
used when evaluating implants. In addition, special sequences are performed that make water and fat dark and silicone bright.
Implant Integrity In the first category, it is important to be aware that the imaging techniques for evaluating silicone implant integrity are vastly different than those for the evaluation of breast cancer. For one, no contrast is
These techniques are not done with traditional breast cancer screening protocols. Therefore, if a clinician is concerned about silicone implant rupture and the answer cannot be ascertained with clinical exam, mammogram or ultrasound, then an
Ashley Hawkins, M.D. has joined the staff at Raleigh Radiology. • BA, University of North Carolina at Chapel Hill • MD, Wake Forest University School of Medicine • Internship in Internal Medicine, Carolinas Medical Center • Residency, Duke University Medical Center • Fellowship in Breast Imaging, Duke University Medical Center
implant protocol breast MRI could be done. Evaluation for implant rupture should be indicated when the MRI is ordered so the appropriate protocol is performed.
Cowden syndrome or Bannayan-RileyRuvalcaba syndrome, or those who may have one of these syndromes based on the history of a first-degree relative. If you are uncertain of your patient’s lifetime risk, you can use the National Cancer Institute’s Breast Cancer Risk Assessment Tool at www.cancer.gov/bcrisktool. Some highrisk breast clinics screen high-risk patients using mammogram one month and then MRI six months later. This allows the patient to have both their mammogram and MRI on an annual basis, yet the patient is undergoing imaging surveillance every six months. New Diagnosis or Prior History The third broad category applies to those women with a new diagnosis of breast cancer
The National Cancer Institute offers a Breast Cancer Risk Assessment Tool at www.cancer.gov/bcrisktool. For the rare case, where silicone implant integrity and breast cancer surveillance are both of concern, rather than have a patient undergo two separate MRIs, evaluation of the implant could be done with mammogram and ultrasound, and then an MRI using the breast cancer protocol could be obtained for breast cancer screening.
or a prior history of breast cancer. Breast MRI is currently the most accurate imaging we have for establishing disease extent (in both the ipsilateral and contralateral breast) in patients with newly diagnosed or recurrent breast cancer. Pre-operative MRI can help establish extent of disease, which better enables the surgeon to get clear margins with only one surgical intervention.
Breast MRI is also used to evaluate for residual disease in the setting of close or positive margins in the post-lumpectomy patient. In addition, in patients undergoing neoadjuvant chemotherapy, MRI can be used to monitor early response to therapy, as well as determine if there is residual cancer at the completion of therapy. Finally, in a small percentage of women, the initial presentation of breast cancer is with metastatic disease to the axillary lymph nodes. In these scenarios, where the primary breast cancer is mammographically occult, an MRI is indicated to locate the site of primary breast cancer. Ideally breast MRI exams are not interpreted by a radiologist in a vacuum. Correlation with recent mammography enhances the strength of the interpretation, and a current mammogram is suggested within a month of the MRI, unless the patient is undergoing high-risk screening. Therefore, if a patient has not had a recent mammogram and she is over age 40, she should get a mammogram at the time she gets her MRI. Finally, the last important point to make is that diagnostic mammogram and ultrasound are still the initial imaging tests for palpable lumps, not MRI.
Breast Cancer Screening The second broad category for the use of breast MRI is breast cancer screening. The American Cancer Society has come out with guidelines for the use of screening MRI. According to these new guidelines, those who are eligible for annual screening breast MRI have one or more of these characteristics: • A known BRCA1 or BRCA2 mutation, • A first-degree relative with the BRCA1 or BRCA2 mutation, • A lifetime risk of breast cancer greater than 20-25 percent, • A history of radiation to the chest between the ages of 10 and 30, • Either Li-Fraumeni syndrome, OCTOBER 2010
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