Breast Imaging: Showing MRI Efficacy vs Mammography

Contrast-enhanced MR-mammography outperforms conventional mammography for almost all patients, tumor types and clinical scenarios. However, recent guidelines still recommend contrast-enhanced MR-mammography for screening in high-risk patients only.

Breast MRI use in community practice

In their observational cohort study from 2014 (JAMA Intern Med) Wernli KJ et al. analyzed data collected from 2005 through 2009 on breast MRI and mammography from five national Breast Cancer Surveillance Consortium registries. Within the five years, more than 1.2 million mammograms had been performed, compared to roughly 8,900 breast MRI examinations

025_26_image-highlight1_report17_20190227_F2R_PAR9551JoergBarkhausen

However, the overall rate of breast MRI from 2005 through 2009 nearly tripled from 4.2 to 11.5 examinations per 1000 women. The most common clinical indications for breast MRI were diagnostic evaluation (40.3%) and screening (31.7%).

Breast Cancer Screening with MRI in BRCA Carriers

Carriers of the ‘BReast CAncer gene’ (BRCA1, BRCA2) have a 5 to 7 times higher cumulative risk of developing breast cancer. Breast cancer onset starts earlier among BRCA carriers.

Phi XA et al. (J Clin Oncol 2015) compared the age-related screening accuracy of breast MRI and mammography in women with BRCA1/2 mutations. Their meta-analysis was based on individual patient data of 1,951 women.

Their result: MRI outperformed mammography and showed much higher sensitivity but a slightly lower specificity compared to mammography independent of age. The sensitivity of mammography was not higher in women older than 50 years. The combination of MRI and mammography showed the best results.

Diagnostic evaluation of clinical and non-MRI imaging findings

In two prospective multicenter trials (GEMMA I and GEMMA II – Invest Radiol 2016) Sardanelli F et al. evaluated the diagnostic efficacy of gadobutrol-enhanced preoperative breast MRI in patients with proven breast cancer.

They showed higher sensitivity for contrast-enhanced MR-mammography compared to conventional mammography. The difference between the two modalities increased with increasing breast density. And even in patients with the lowest ACR Version 5 density grade A, MR-mammography showed higher sensitivity than conventional mammography.

Preoperative Breast MRI – Staging

The same data set of the GEMMA studies was used to compare both modalities for their potential to detect additional cancer manifestations. Compared to mammography, contrast-enhanced MR-mammography showed significantly higher sensitivity for the detection of additional cancers. Also in this setting, the difference between the two modalities increased with increasing breast density.

Follow-up after Breast Conserving Therapy

Gweon HM et al. (Radiology 2014) investigated the outcomes of single-screening breast MRI in women with a history of breast conserving therapy for breast cancers and with previous negative mammography and ultrasound findings.

In 607 women, eleven cancers were additionally detected with MR imaging (18.1 cancers per 1000 women).

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Clinical Guidelines – Surveillance after Breast Conserving Therapy

Swinnen J et al. (Insights Imaging 2018) systematically analyzed 18 guidelines published between 2007 and 2017 on what they recommend for breast imaging surveillance after curative treatment for primary non-metastasized breast cancer in non-high-risk women.

17 out of 18 guidelines recommended annual bilateral mammography. Only one guideline recommended routine use of digital breast tomosynthesis, two recommended routine breast ultrasound. 16/18 guidelines did not recommend contrast-enhanced MRI; 6/18 guidelines at least recommended contrast-enhanced MRI for subgroups such as young patients and patients with dense breast tissue.

Public Discussion

Chairwoman Lale Umutlu, Germany, asked Barkhausen why breast MRI does not transfer to clinical guidelines up to now? Barkhausen said, besides financial reasons it might be the fact that MRI is still time consuming. Furthermore, “the other modalities are performing excellently as well – we have strong competitors”.

References

Gweon HM et al. Breast MR imaging screening in women with a history of breast conservation therapy. Radiology. 2014 Aug;272(2):366-73.

Phi XA et al. Magnetic resonance imaging improves breast screening sensitivity in BRCA mutation carriers age ≥ 50 years: evidence from an individual patient data meta-analysis. J Clin Oncol. 2015 Feb 1;33(4):349-56.

Sardanelli F et al. Gadobutrol-Enhanced Magnetic Resonance Imaging of the Breast in the Preoperative Setting: Results of 2 Prospective International Multicenter Phase III Studies. Invest Radiol. 2016 Jul;51(7):454-61.

Swinnen J. et al. Breast imaging surveillance after curative treatment for primary non-metastasised breast cancer in non-high-risk women: a systematic review Insights Imaging 2018;9:961-70.

Wernli KJ et al. Patterns of breast magnetic resonance imaging use in community practice. JAMA Intern Med. 2014 Jan;174(1):125-32.

Presentation Title: Showing MRI efficacy vs mammography
Speaker: J. Barkhausen, University of Luebeck, Germany
Date: February 27 2019
Session code: SY 2a