The use of MRI before breast surgery is increasing based on reports that show that MRI can detect previously unknown foci of breast cancer in a substantial number of women with a new diagnosis of breast cancer. However, some argue that MRI will increase the proportion of mastectomy because it will cause more extensive surgeries. Since breast conservation surgery combined with radiation therapy as major advantages with similarly low recurrence rates and equivalent mortality, an increase in the rate of mastectomy prompted by MRI findings would be a negative development. Since studies have shown equivalent outcomes for lumpectomy with radiation and mastectomy, the implied argument is that the MRI just cause more extensive surgeries and not improve the results. Even if some foci are missed, preoperative MRI would have little or no impact on rates of recurrence or death because of post-operative radiation. For this reason, MRI should not be used routinely in the workup of new breast cancers.
American Society of Brat Imaging does recommend MRI to aid the assessment for eligibility and response to neoadjuvant endocrine therapy or chemotherapy before, during, or after treatment. MRI can help identify those patients who are candidates for breast conservation, and assist in determining the extent of resection.
National Comprehensive Cancer Network, . Clinical practice guidelines in oncology. Genetic/familial high-risk assessment: breast and ovarian cancer. www.nccn.org/professionals/physician_gls/f_guidelines.asp. 2018
American Society of Brast Imaging, https://www.gfmer.ch/Guidelines/Breast_diseases/Breast_imaging.htm
Morrow M, Freedman G . A clinical oncology perspective on the use of breast MR. Magn Reson Imaging Clin N Am 2006; 14:363–378.
Schnall MS MR imaging of cancer extent: is there clinical relevance? Magn Reson Imaging Clin N Am 2006; 14:379–381
LOUIE ENRIQUEZ, MD Role of MRI in breast cancer management Cleveland Clinic Journal of Medicine September 2009 vol. 76 9 525-532
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