The role of breast MRI in the management of patients with breast disease

Robust breast quantitative susceptibility mapping in the presence of silicone

PURPOSE

To (a) develop a preconditioned water-fat-silicone total field inversion (wfsTFI) algorithm that directly estimates the susceptibility map from complex multi-echo data in the breast in the presence of silicone and to (b) evaluate the performance of wfsTFI for breast quantitative susceptibility mapping (QSM) in silico and in vivo in comparison with formerly proposed methods.

METHODS

Numerical simulations and in vivo multi-echo gradient echo breast measurements were performed to compare wfsTFI to a previously proposed field map-based linear total field inversion algorithm (lTFI) with and without the consideration of the chemical shift of silicone in the field map estimation step. Specifically, a simulation based on an in vivo scan and data from five patients were included in the analysis.

RESULTS

In the simulation, wfsTFI is able to significantly decrease the normalized root mean square error from lTFI without (4.46) and with (1.77) the consideration of the chemical shift of silicone to 0.68. Both the in silico and in vivo wfsTFI susceptibility maps show reduced shadowing artifacts in local tissue adjacent to silicone, reduced streaking artifacts and no erroneous single voxels of diamagnetic susceptibility in proximity to silicone.

CONCLUSION

The proposed wfsTFI method can automatically distinguish between subjects with and without silicone. Furthermore wfsTFI accounts for the presence of silicone in the QSM dipole inversion and allows for the robust estimation of susceptibility in proximity to silicone breast implants and hence allows the visualization of structures that would otherwise be dominated by artifacts on susceptibility maps.

Evaluation of a continuous-time random-walk diffusion model for the differentiation of malignant and benign breast lesions and its association with Ki-67 expression

The purpose of the current study was to evaluate the performance of a continuous-time random-walk (CTRW) diffusion model for differentiating malignant and benign breast lesions and to consider the potential association between CTRW parameters and the Ki-67 expression. Sixty-four patients (46.2 ± 11.4 years) with breast lesions (29 malignant and 35 benign) were evaluated with the CTRW model, intravoxel incoherent motion model, and diffusion-weighted imaging. Echo planar diffusion-weighted imaging was conducted using 13 b-values (0-3000 s/mm² ). Three CTRW model parameters, including an anomalous diffusion coefficient D_m , and two parameters related to temporal and spatial diffusion heterogeneity, α and β, respectively, were obtained, and had MRI b-values of 0-3000 s/mm² . Receiver operating characteristic (ROC) analysis was conducted to determine the sensitivity, specificity, and diagnostic accuracy of CTRW parameters for differentiating malignant from benign breast lesions. In malignant breast lesions, the CTRW parameters D_m , α, and β were significantly lower than the corresponding parameters of benign breast lesions. In the malignant breast lesion group, the CTRW parameter D_m was significantly lower in high Ki-67 expression than in low Ki-67 expression. In ROC analysis, the combination of CTRW parameters (D_m , α, β) demonstrated the highest area under the curve value (0.985) and diagnostic accuracy (94.23%) in differentiating malignant and benign breast lesions. The CTRW model effectively differentiated malignant from benign breast lesions. The CTRW diffusion model offers a new way for noninvasive assessment of breast malignancy and better understanding of the proliferation of malignant lesions.

A Retrospective Study Evaluating the Impact of Preoperative Breast MRI on Surgical Decision-Making in Young Patients (≤50 Years) with Invasive Breast Cancer

INTRODUCTION

Breast magnetic resonance imaging (MRI) is considered a more sensitive diagnostic test for detecting invasive breast cancer than mammography or breast ultrasound. Breast MRI may be particularly useful in younger premenopausal women with higher density breast tissue for differentiating between dense fibroglandular breast tissue and breast malignancies. The main objective of this study was to determine the impact of preoperative breast MRI on surgical decision-making in young women with breast cancer.

METHODS

A retrospective review of patients with newly diagnosed invasive breast cancer and age of ≤50 years was performed. All patients underwent physical examination, preoperative mammogram, breast ultrasound, and bilateral breast MRI. Two breast cancer surgeons reviewed the preoperative mammogram report, breast ultrasound report, and physical examination summary and were asked if they would recommend a lumpectomy, a quandrantectomy, or a mastectomy. A few weeks later, the two surgeons were shown the same information with the breast MRI report and were asked what type of surgery they would now recommend. In each case, MRI was classified by two adjudicators as having affected the surgical outcome in a positive, negative, or neutral fashion. A positive impact was defined as the situation where breast MRI detected additional disease that was not found on physical examination, mammogram, or breast ultrasound and led to an appropriate change in surgical management. A negative impact was defined as the situation where breast MRI led the surgeon to recommend more extensive surgery, with less extensive disease actually found at pathology. No impact was defined as the situation where MRI findings did not alter surgical recommendations or outcomes.

RESULTS

Of 37 patients whose charts were reviewed, five patients were deemed to be ineligible due to having received neoadjuvant chemotherapy, having previous breast implants, or having had their tumor fully excised during biopsy. In total, 32 patients met the inclusion criteria of this study and were appropriate for analysis. The median age of our study patient population was 42 years. The pathologic diagnosis was invasive ductal carcinoma in 91% (29/32) of patients and invasive lobular carcinoma in 9% (3/32) of patients. For surgeon A, clinical management was altered in 21/32 (66%) patients, and for surgeon B, management was altered in 13/32 (41%) patients. The most common change in surgical decision-making after breast MRI was from breast-conserving surgery to a mastectomy. Mastectomy rates were similar between both surgeons after breast MRI. After reviewing the pathology results and comparing them with the breast MRI results, it was determined that breast MRI led to a positive outcome in 13/32 (41%) patients. Breast MRI led to no change in surgical management in 15/32 (47%) patients and resulted in a negative change in surgical management in 4/32 (13%) patients. Bilateral breast MRI detected a contralateral breast cancer in 2/32 (6%) patients.

CONCLUSIONS

Preoperative breast MRI alters surgical management in a significant proportion of younger women diagnosed with breast cancer. Prospective studies are needed to confirm these findings and to help determine if this change in surgical decision-making will result in improved local control.

Clinical and morphological factors predictive of occult involvement of the nipple-areola complex in mastectomy specimens

OBJECTIVE

To evaluate characteristics predictive of nipple-areola complex (NAC) involvement by the breast tumor.

STUDY DESIGN

Cases of infiltrative ductal carcinoma (stages I, IIA and IIB) treated by mastectomy in which the distance between the tumor and the NAC was >or=2 cm were included. NAC involvement was evaluated using serial histological sections. The distance between the tumor and the NAC was measured on mammograms. Other parameters taken into consideration were: tumor size, histological and nuclear grades, vascular invasion, and the presence of an in situ component. For comparisons between categorical variables, the chi-square test or Fisher's exact test were used. Student's t-test was used for numerical variables with normal distribution and the Mann-Whitney U-test was applied when distribution was not normal.

RESULTS

Fifty patients were included. NAC was affected in 12 and unaffected in 38. There was no statistically significant difference in mean age between the unaffected and affected groups (58.9+/-13.5 years versus 55.8+/-12.5 years, p=0.477); however, 13.2% and 58.3% (p=0.046) in the NAC-unaffected and NAC-affected groups, respectively, were <50 years of age. Distance <or=3 cm between the tumor and the NAC on mammograms was found in 60.5% of the NAC-unaffected group and in 100% of the NAC-affected group (p=0.007). With respect to the in situ component, there was a difference between the NAC-unaffected and NAC-affected groups regarding micropapillary pattern (13.2% versus 50.0%; p=0.014) and extensive in situ component (13.2% versus 41.7%; p=0.046). No statistically significant difference was found for any of the other parameters analyzed.

CONCLUSIONS

A distance between the tumor and the NAC <or=3 cm, age <50 years, and ductal carcinoma in situ with micropapillary pattern or with an extensive in situ component were factors significantly associated with a higher likelihood of NAC involvement.

Tumor marker phenotype concordance in second primary breast cancer, California, 1999-2004

Breast cancer is the most common cancer among women. It is estimated that 7% of women who have breast cancer will develop a subsequent second independent breast tumor within 10 years of the first. The status of estrogen (ER), progesterone (PR) and human growth hormone (HER2) receptors, individually and as phenotypic combinations, impacts the clinical course of breast cancer and may impact the course of subsequent primary tumors and patient survival. Our aims were to determine tumor marker phenotype concordance between first and second primary breast cancers (FPBC and SPBC), describe demographic and clinical characteristics, and examine first tumor treatments associated with phenotype concordance. A total of 76,209 cases of female invasive breast cancer were identified in the California Cancer Registry from 1999 to 2004. Of those, 1,407 women who had not undergone a prophylactic mastectomy, had information on the status of three tumor markers, and were diagnosed with an SPBC during the study period were selected. SPBCs were significantly smaller, diagnosed at a higher stage and were node positive. Patients whose FPBC was ER(+)/-/PR(+)/-/HER2- and triple negative (TN) (ER-/PR-/HER2-), often had concordant phenotypes for their SPBC. ER(+)/-/PR(+)/-/HER2+ and HER2-positive (ER-/PR-/HER2+) FPBCs, often had discordant phenotypes for their SPBC. ER(+)/-/PR(+)/-/HER2- SPBCs often lacked HER2 expression and were ER and/or PR positive. Tumor laterality and synchronicity significantly predicted concordance as did having a FPBC whose phenotypes were ER(+)/-/PR(+)/-/HER2+, HER2-positive and TN, while first primary tumor treatment with chemotherapy predicted discordance. The relationship between multiple primary breast cancer phenotype concordance and patient prognosis has yet to be determined. Our results indicate that SPBC surveillance strategies include consideration of FPBC phenotype. Although our results are provocative, they may have been influenced by current criteria used to determine tumor independence.

[Diagnosis of breast cancer in women age 40 and younger: mammography and breast ultrasound]

Breast cancer is the leading cause of mortality among women aged 25 to 44 years in Serbia. The purpose of this study was to determine basic clinical and radiological features of breast cancer in young women. 93 women aged 31.0 +/- 3.5 years with breast cancer were identified. The analysis included clinical characteristics (TNM classification) and radiological features (mammography and breast ultrasound). 53.8% of the patients had locoregional disease. The mean diameter of breast cancer was 2.6 +/- 6 cm. Carcinoma in situ was found in 2.2%. Mammography was performed in 25.8% of the patients and breast ultrasound in 68.8%. The results of our study indicate that the diagnosis of breast cancer in young women is late, in the stage with palpable breast tumor and lymph node metastases. Mammography or breast ultrasound are not routinely used. The implementation of algorithms for breast cancer detection and diagnosis in young women helps in earlier detection of breast cancer and consequently improves outcomes.