Breast MRI Update. Jeffrey C. Weinreb, MD, FACR Yale University School of Medicine

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1 Breast MRI Update Jeffrey C. Weinreb, MD, FACR Yale University School of Medicine

2 I disclose the following financial relationships with relevant commercial interests: Bracco Bayer Healthcare CME Consultant, Research Support, CME

3 Topics Is Breast MRI beneficial? Can Breast MRI reliably diagnose DCIS? Is Breast MRI better at 3T? What is the ACR Breast MRI Accreditation Program?

4 American Cancer Society recommends annual MRI screening for women with >20% lifetime risk of breast cancer CA Cancer J Clin 2007;57:75-89 BRCA gene mutation carriers First-degree relative of BRCA carrier, but untested Lifetime risk: >20%, as defined by BRCAPRO or other models (eg( eg. Tyrer- Cuzick) ) that are largely dependent on family history Estimated to effect 1.7 million women

5 Is it cost effective? Breast MR screening is more cost-effective for BRCA1 than BRCA2 mutation carriers, and cost effectiveness varies greatly with age Plevritis SK, et al. JAMA 2006 Breast MR screening is cost effective for BRCA1 & BRCA2 mutation carriers Gribsh I, et al. British Journal of Cancer 2006 Breast MR screening is cost effective for BRCA1 & BRCA2 mutation carriers by current standards, and it may also be cost-effective effective in other high risk groups Taneja C, et al. JACR 2009

6 Does it reduce mortality? Annual screening with combined mammography and MRI improves life expectancy and decreases breast cancer mortality for BRCA1 mutation carriers Trade-off is high rate of false-positive results and subsequent biopsies for benign disease Lee JM, et al. Radiology 2008

7 Who should undergo MRI prior to surgery? Dense breasts BRCA gene mutation carriers Other patients with high risk Mammographically occult cancer Suspect chest wall involvement Everyone? Difficult histology (eg( eg.. invasive lobular carcinoma) Candidates for neoadjuvant chemotherapy

8 Accuracy and surgical impact of magnetic resonance imaging in breast cancer staging: systematic review and meta-analysis in detection of multifocal and multicentric breast cancer false-positive findings on MRI have the potential to complicate rather than improve preoperative assessment for women with newly diagnosed breast cancer and may lead to wider resection than necessary. The current body of knowledge indicates that while MRI has substantial detection yield for additional disease within the affected breast, identifying these additional (otherwise occult) cancer foci does not lead to better preoperative planning and surgical treatment. Houssani N, et al. JCO 2008

9 DCIS Heterogeneous group of lesions with variable genetic, biologic, and histologic features Generally considered a nonobligate precursor of invasive cancer 30-50% will become invasive 10-25% diagnosed with mammography will never proceed to invasive cancer and will remain dormant during a woman s s life 20% of mammographically detected cancers Mammographic detection is based on depiction of microcalcifications (probably caused by necrosis secondary to hypoxia) Mammography misses many DCIS lesions because hypoxia and calcification are not always present

10 Pure DCIS Evaluated 79 pure DCIS lesions 68% showed rapid enhancement Display a variety of enhancement kinetic curves 44% washout 25% plateau 31% persistent Predominant MR morphology is nonmass and clumped, heterogeneous, or homogeneous in a segmental or linear distribution Enhancement kinetics vary according to mammographic appearance but not according to nuclear grade Lesions with fine pleomorphic,, fine liner, or fine liner-branching calcifications or that appear as masses on mammograms have stronger washout 691 Jansen SA, et al. Radiology 2007;245:684-

11 MRI of DCIS Reported sensitivity of CE-MRI for detection of DCIS is 77-96% 48% of high grade DCIS were visible on MR but missed on mammography Approx 20% of low grade DCIS do not enhance, but some may be diagnosed with mammography Kuhl CK, et al. Lancet 2007;370 (9586):

12 DCIS-containing ducts are fed by diffusion from extraductal vessels Enhance due to increase permeability of the basement membrane (secondary to increased protease activity induced by intraductal cancers) Hypoxia and calcification are not required for enhancement MRI enhancement may be a biomarker that predicts the natural behavior of DCIS (i.e. progression to invasive cancer) Jansen SA, et al. Radiology 2009;253:

13 Materials and Methods: 37 women with 53 lesions who underwent MRI twice, once at 1.5T and once at 3.0T Results: Overall image quality was slightly higher at 3.0T (P <.01) Differential diagnosis of enhancing lesions was possible with higher diagnostic confidence Kuhl CK, et al. Radiology 2006;239:

14 42 yo with fibroadenomas High res delayed axial Acquired post c ax Acquired post c sag Reformatted sag 1.5T 3T

15 424 women at high risk for breast cancer Sensitivity was higher than those most reported at 1.0 and 1.5T Elsamaloty H, et al. AJR 2009;192:

16 Breast MRI at 3T BENEFITS Increased SNR (depends on tissue and pulse sequence) Faster Higher spatial resolution Higher bandwidth imaging Signal poor techniques eg.. DWI & PA More effective enhancement with GBCA MRSI Higher peaks Greater spectral dispersion Better fat suppression C, O,, Na, P Increased susceptibility Lower doses Gd for same perfusion effect Better BOLD effect CHALLENGES Contrast relationships change Longer T1 of breast glandular tissue by 100 msec (approx 14%) requires modifications (increase TR or decrease FA) Little change in T2 Availability of RF coils Safety issues Artifacts Chemical shift Susceptibility RF magnetic field (B 1 ) inhomogeneity

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