Breast magnetic resonance imaging: An essential role in malignant axillary lymphadenopathy of unknown origin

Real-Time MRI Navigated Ultrasound for Preoperative Tumor Evaluation in Breast Cancer Patients: Technique and Clinical Implementation

Real-time magnetic resonance imaging (MRI) navigated ultrasound is an image fusion technique to display the results of both MRI and ultrasonography on the same monitor. This system is a promising technique to improve lesion detection and analysis, to maximize advantages of each imaging modality, and to compensate the disadvantages of both MRI and ultrasound. In evaluating breast cancer stage preoperatively, MRI and ultrasound are the most representative imaging modalities. However, sometimes difficulties arise in interpreting and correlating the radiological features between these two different modalities. This pictorial essay demonstrates the technical principles of the real-time MRI navigated ultrasound, and clinical implementation of the system in preoperative evaluation of tumor extent, multiplicity, and nodal status in breast cancer patients.

Supine breast US: how to correlate breast lesions from prone MRI

OBJECTIVE

To evaluate spatial displacement of breast lesions from prone MR to supine ultrasound positions, and to determine whether the degree of displacement may be associated with breast density and lesion histotype.

METHODS

380 patients underwent breast MR and second-look ultrasound. The MR and ultrasound lesion location within the breast gland, distances from anatomical landmarks (nipple, skin and pectoral muscle), spatial displacement (distance differences from the landmarks within the same breast region) and region displacement (breast region change) were prospectively evaluated. Differences between MR and ultrasound measurements, association between the degree of spatial displacement and both breast density and lesion histotypes were calculated.

RESULTS

In 290/380 (76%) patients, 300 MR lesions were detected. 285/300 (95%) lesions were recognized on ultrasound. By comparing MR and ultrasound, spatial displacement occurred in 183/285 (64.3%) cases while region displacement in 102/285 (35.7%) cases with a circumferential movement along an arc centred on the nipple, having supine ultrasound as the reference standard. A significant association between the degree of lesion displacement and breast density was found (p < 0.00001) with a significant higher displacement in case of fatty breasts. No significant association between the degree of displacement and lesion histotype was found (p = 0.1).

CONCLUSION

Lesion spatial displacement from MRI to ultrasound may occur especially in adipose breasts. Lesion-nipple distance and circumferential displacement from the nipple need to be considered for ultrasound lesion detection.

ADVANCES IN KNOWLEDGE

Second-look ultrasound breast lesion detection could be improved by calculating the lesion-nipple distance and considering that spatial displacement from MRI occurs with a circumferential movement along an arc centred on the nipple.

Breast conservation in the setting of contemporary multimodality treatment provides excellent outcomes for patients with occult primary breast cancer

PURPOSE

To evaluate recurrence and survival for patients with occult (T0N+) breast cancer who underwent contemporary treatment, assessing outcomes for breast conservation and mastectomy.

METHODS

We performed a single-institution review of women with occult breast cancer presenting with axillary metastasis without identifiable breast tumor or distant metastasis. We excluded patients with tumors in the axillary tail or mastectomy specimen, patients with additional nonbreast cancer diagnoses, and patients with a history of breast cancer. Breast conservation was defined as axillary node dissection with radiation therapy, without breast surgery. We evaluated patient, tumor, treatment, and outcome variables. Patients were assessed for local, regional, and distant recurrences. Overall survival was calculated using the Kaplan-Meier method.

RESULTS

Thirty-six patients met criteria for occult breast cancer. Most of these patients (77.8 %) had N1 disease. Fifty percent of cancers (n = 18) were estrogen receptor-positive; 12 (33.3 %) were triple-negative. All patients were evaluated with mammography. Thirty-five patients had breast ultrasound (97.2 %) and 33 (91.7 %) had an MRI. Thirty-four patients (94.4 %) were treated with chemotherapy and 33 (91.7 %) with radiotherapy. Twenty-seven patients (75.0 %) were treated with breast conservation. The median follow-up was 64 months. There were no local or regional failures. One distant recurrence occurred >5 years after diagnosis, resulting in a 5-years overall survival rate of 100 %. There were no significant survival differences between patients receiving breast conservation versus mastectomy (p = 0.7).

CONCLUSIONS

Breast conservation-performed with contemporary imaging and multimodality treatment-provides excellent local control and survival for women with T0N+ breast cancer and can be safely offered instead of mastectomy.

Applications for breast magnetic resonance imaging

This article reviews the relevant data on breast magnetic resonance imaging (MRI) use in screening, the short-term surgical outcomes and long-term cancer outcomes associated with the use of MRI in breast cancer staging, the use of MRI in occult primary breast cancer, as well as MRI to assess eligibility for accelerated partial breast irradiation and to evaluate tumor response after neoadjuvant chemotherapy. MRI for screening is supported in specific high-risk populations, namely, women with BRCA1 or BRCA2 mutations, a family history suggesting a hereditary breast cancer syndrome, or a history of chest wall radiation.

Geographic and temporal trends in the management of occult primary breast cancer: a systematic review and meta-analysis

BACKGROUND

Management of occult primary breast cancer (OPBC), including the role of magnetic resonance imaging (MRI), is controversial. We conducted a pooled analysis of OPBC patients and a meta-analysis of MRI accuracy in OPBC in order to elucidate current practices.

METHODS

A literature search yielded 201 studies. Patient-level data for clinically/mammographically OPBC from studies published after 1993 and from our institution were pooled; logistic regression examined associations between patient/study data and outcomes, including treatments and recurrence. We report adjusted odds ratios (OR) and 95 % confidence intervals (95 % CI) significant at 2-tailed p < 0.05. Meta-analysis included data for patients who received MRIs for workup of clinically/mammographically OPBC. We report pooled sensitivity and specificity with 95 % CIs.

RESULTS

The pooled analysis included 92 patients (15 studies [n = 85] plus our institution [n = 7]). Patients from Asia were more likely to receive breast surgery (OR = 5.98, 95 % CI = 2.02-17.65) but not chemotherapy (OR = 0.32, 95 % CI = 0.13-0.82); patients from the United States were more likely to receive chemotherapy (OR = 13.08, 95 % CI = 2.64-64.78). Patients from studies published after 2003 were more likely to receive radiotherapy (OR = 3.86, 95 % CI = 1.41-10.55). Chemotherapy recipients were more likely to have distant recurrence (OR = 9.77, 95 % CI = 1.10-87.21). More patients with positive MRIs received chemotherapy than patients with negative MRIs (10 of 12 [83.3 %] vs 5 of 13 [38.5 %]; p = 0.0414). In the MRI-accuracy meta-analysis (10 studies, n = 262), pooled sensitivity and specificity were 96 % (95 % CI = 91-98 %) and 63 % (95 % CI = 42-81 %), respectively.

CONCLUSIONS

OPBC management varied geographically and over time. We recommend establishing an international OPBC patient registry to facilitate longitudinal study and develop global treatment standards.

Impact of breast MR in non-screening Australian clinical practice: audit data from a single-reader single-centre site

AIM

The aim of this study was to evaluate the accuracy and clinical impact of single-reader breast MR (BMR) used as a clinical 'problem solving' tool.

METHODS

Observational, retrospective, ethics approved data collection for all BMR were from May 2006 to February 2009 (n=143). Cases were stratified into groups according to indication for referral. MR data included single-reader MR diagnosis and breast imaging reporting and data system category (per-patient basis), MR descriptors of lesions (breast imaging reporting and data system lexicon), lesion number and location. Composite reference standard was established from surgical histology, core histology, cytology, MR imaging follow-up, conventional imaging follow-up and clinical follow-up in that order of priority. Impact was qualitatively captured by estimating change in management as the result of BMR.

RESULTS

Eighty-two cases were included and 61 were excluded (41 insufficient follow-up times, three known benign mass for clarification, two worried well screening and 15 other reasons). There was no statistically significant difference in included and excluded patient profiles. Our largest group of referrals was of patients with suspicious or unhelpful conventional imaging. BMR identified five malignancies in that group but missed four. In our smaller group of patients with metastatic axillary lymph nodes, BMR identified the occult primary cancer in all five cases.

CONCLUSION

In this 'problem solving' patient population, breast MR shows greatest impact in patients with carcinoma metastases to axillary nodes, but primary not visible. In symptomatic women with unhelpful imaging or with suspicious imaging but no pre-MR diagnosis, MR identified 5/41 carcinomas, but missed 4/41.

Magnetic resonance imaging for screening, diagnosis, and eligibility for breast-conserving surgery: promises and pitfalls

Magnetic resonance imaging (MRI) is able to visualize small tumor deposits that previously could only be identified on pathologic examination. MRI is most valuable in areas in which patient management has been problematic, including screening women with known or suspected BRCA 1 and 2 mutations, and identification of the primary tumor site in patients presenting with axillary adenopathy. The role of MRI in the patient with newly diagnosed breast cancer remains controversial. Success rates for patients selected for breast-conserving therapy without MRI are high, and rates of ipsilateral breast tumor recurrence are low. Future efforts to improve the local therapy for breast cancer must acknowledge the heterogeneity of the disease and tailor approaches to the biology of individual subsets. This goal can only be accomplished through a multidisciplinary approach that examines the applications of newer diagnostic modalities such as MRI.