Magnetic resonance imaging in the preoperative evaluation of breast cancer: primum non nocere

Additional breast lesions on MRI in patients with small early stage luminal type breast cancer: Important consequences for future thermal ablation treatment

In this study, data from 50 postmenopausal women with unilateral cT1N0 breast cancer, who underwent MRI as part of the THERMAC trial for a thermal ablation protocol, were analyzed. Additional MRI findings were classified as benign or malignant based on histopathology. Results showed that 30 % of patients had additional MRI findings, with 40 % of those being malignant, which led to exclusion from the trial and altered surgical management. Malignant lesions included lobular carcinoma, NST tumors, and multifocal/multicentric disease, while benign findings were predominantly fibroadenomas, cysts, and mastopathy. Malignant lesions required changes in the treatment approach, including exclusion from the ablation protocol, wider excisions, and in some cases, mastectomy. The study highlights the significant role of MRI in patient selection and treatment planning, emphasizing the need for further investigation into the long-term oncological outcomes in early-stage breast cancer patients.

Diagnostic role of dynamic contrast-enhanced magnetic resonance imaging in differentiating breast lesions

OBJECTIVE

This study aimed to assess the diagnostic role of perfusion weighted image (DCE-PWI) to differentiate benign from malignant breast lesions.

PATIENTS AND METHODS

The study comprised 32 women who had mammography and/or breast ultrasonography findings that were clinically questionable. All patients were fasting during the magnetic resonance imaging (MRI) test to avoid nausea or dynamic contrast-enhanced vomiting from the contrast medium.

RESULT

In this study, we observed the form of the dynamic curve (time and signal intensity curve) type I (persistent curve) was noted in 12 lesions (37.5%): 10 lesions were benign and two lesions were malignant; type II (plateau curve) was noted in eight lesions (25%): three lesions were benign and five lesions were malignant, and type III (washout curve) noted in 12 lesions (37.5%): one lesion was benign and 11 lesions were malignant.

CONCLUSIONS

The dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) perfusion technique plays an important role in differentiating benign and malignant tumors in breast cancer.

Screening, imaging, and image-guided biopsy techniques for breast cancer

Mammography remains the primary modality for breast cancer diagnosis. Other imaging studies, most commonly ultrasonography and magnetic resonance imaging, are also used to characterize breast lesions, stage breast cancer, and aid in surgical planning. Although mammography is the only screening examination demonstrated to decrease breast cancer mortality in the general population, other imaging studies have been shown to be beneficial for screening high-risk patients. In the future, new technologies may also improve the sensitivity and specificity of breast cancer screening and detection.

Locally advanced breast cancer: MR imaging for prediction of response to neoadjuvant chemotherapy--results from ACRIN 6657/I-SPY TRIAL

Purpose

This study was designed to determine (1) rates of clinically meaningful tumor reduction in breast tumor size following neoadjuvant chemotherapy (NAC), (2) which receptor subtypes and MRI phenotypes are associated with clinically meaningful tumor reduction, and (3) whether MRI phenotype impacts concordance between pathologic and MRI size.

Methods

We analyzed data from the I-SPY TRIAL, a multicenter, prospective NAC trial. Reduction in tumor size from >4 to ≤4 cm was considered clinically meaningful, as crossing this threshold was considered a reasonable cutoff for potential breast conservation therapy (BCT). MRI phenotypes were scored between one (well-defined) and five (diffuse) on pre-NAC MRIs.

Results

Of 174 patients with tumors >4 cm, 141 (81 %) had clinically meaningful tumor reduction. Response to therapy varied by MRI phenotype (p = 0.003), with well-defined phenotypes more likely than diffuse phenotypes to have clinically meaningful tumor shrinkage (91 vs. 72 %, p = 0.037). Her2+ and triple-negative (Tneg) tumors had the highest rate of clinically meaningful tumor reduction (p = 0.005). The concordance between tumor diameter on MRI and surgical pathology was highest for Her2+ and Tneg tumors, especially among tumors with solid imaging phenotypes (p = 0.004).

Discussion

NAC allows most patients with large breast tumors to have clinically meaningful tumor reduction, meaning response that would impact ability to undergo BCT. However, response varies by imaging and tumor subtypes. Concordance between tumor size on MRI and surgical pathology was higher in well-defined tumors, especially those with a Tneg subtype, and lower in HR+ diffuse tumors.

Electronic supplementary material

The online version of this article (doi:10.1245/s10434-013-3038-y) contains supplementary material, which is available to authorized users.

An anthropomorphic phantom for quantitative evaluation of breast MRI

PURPOSE

In this study, the authors aim to develop a physical, tissue-mimicking phantom for quantitative evaluation of breast MRI protocols. The objective of this phantom is to address the need for improved standardization in breast MRI and provide a platform for evaluating the influence of image protocol parameters on lesion detection and discrimination. Quantitative comparisons between patient and phantom image properties are presented.

METHODS

The phantom is constructed using a mixture of lard and egg whites, resulting in a random structure with separate adipose- and glandular-mimicking components. T1 and T2 relaxation times of the lard and egg components of the phantom were estimated at 1.5 T from inversion recovery and spin-echo scans, respectively, using maximum-likelihood methods. The image structure was examined quantitatively by calculating and comparing spatial covariance matrices of phantom and patient images. A static, enhancing lesion was introduced by creating a hollow mold with stereolithography and filling it with a gadolinium-doped water solution.

RESULTS

Measured phantom relaxation values fall within 2 standard errors of human values from the literature and are reasonably stable over 9 months of testing. Comparison of the covariance matrices of phantom and patient data demonstrates that the phantom and patient data have similar image structure. Their covariance matrices are the same to within error bars in the anterior-posterior direction and to within about two error bars in the right-left direction. The signal from the phantom's adipose-mimicking material can be suppressed using active fat-suppression protocols. A static, enhancing lesion can also be included with the ability to change morphology and contrast agent concentration.

CONCLUSIONS

The authors have constructed a phantom and demonstrated its ability to mimic human breast images in terms of key physical properties that are relevant to breast MRI. This phantom provides a platform for the optimization and standardization of breast MRI imaging protocols for lesion detection and characterization.

MR-guided vacuum-assisted breast biopsy in the management of incidental enhancing lesions detected by breast MR imaging

PURPOSE

The objective of this study was to determine the clinical value and accuracy of magnetic resonance (MR)-guided vacuum-assisted breast biopsy (VAB).

MATERIALS AND METHODS

We retrospectively analysed 106 incidental breast lesions detected on MR imaging in 98 patients. Patients with nonpalpable suspicious lesions that were only MR visible were referred for MR-VAB performed with a 10-gauge needle. All patients with a VAB diagnosis of infiltrating carcinoma, carcinoma in situ or atypical epithelial hyperplasia were referred for surgery. Histopathology of the surgical specimen was considered the reference standard.

RESULTS

MR-guided VAB was attempted in 29/106 lesions (27%); in 2/29 patients, the procedure could not be performed owing to failure to visualise the lesion. Lesions with clearly malignant features and borderline lesions (atypical ductal hyperplasias) were identified in 12 cases (44%) and benign entities in 15 (56%). Seven of 12 (58%) malignant lesions were <10 mm. Among the 27 successful MR-VAB procedures, VAB yielded one false-negative diagnosis (4%) and underestimation (4%). MR-guided VAB sensitivity and specificity were 92% and 100%, respectively, with a positive predictive value of 100% and a negative predictive value of 93%.

CONCLUSIONS

The results of this study indicate that MR-guided VAB offers good accuracy in characterising nonpalpable breast lesions visible on MR imaging alone. Small lesion size (<1 cm) did not prove to be a limitation for the success of the procedure.

Role of MRI (magnetic resonance imaging) versus conventional imaging for breast cancer presurgical staging in young women or with dense breast

AIMS

The role of magnetic resonance imaging (MRI) in the local staging of breast cancer is currently uncertain. The purpose of this prospective study is to evaluate the accuracy of preoperative MRI compared to conventional imaging in detecting breast cancer and the effect of preoperative MRI on the surgical treatment in a subgroup of women with dense breasts, young age, invasive lobular cancer (ILC) or multiple lesions.

METHODS

Between January 2006 and October 2007, 91 patients with newly diagnosed breast cancer underwent preoperative clinical breast examination, mammography, bilateral breast ultrasonography and high-resolution breast MRI. All patients had histologically verified breast cancer. The imaging techniques were compared using the final pathological report as gold standard.

RESULTS

The sensitivity of MRI for the main lesion was 98.9%, while for multiple lesions sensitivity was 90.7% and specificity 85.4%. After preoperative MRI, 13 patients (14.3%) underwent additional fine needle/core biopsies, 9 of whom had specimen positive for cancer. Preoperative MRI changed the surgical plan in 26 patients: in 19.8% of the cases breast conservative surgery was converted to mastectomy and in 7.7% of the patients a wider excision was performed. At a mean follow-up of 48 months, 2 local recurrences occurred (local failure rate = 2.5%).

CONCLUSIONS

Enhanced sensitivity of breast MRI may change the surgical approach, by increasing mastectomy rate or suggesting the need of wider local excision. MRI can play an important role in preoperative planning if used in selected patients with high risk of multifocal/multicentric lesions. However, the histologic confirmation of all suspicious findings detected by MRI is mandatory prior to definite surgery.

Vacuum-assisted biopsies under MR guidance: results of 72 procedures

OBJECTIVE

To investigate the clinical accuracy of magnetic resonance imaging-guided breast vacuum-assisted biopsy (MR-VAB).

METHODS

Of 97 scheduled MR-VAB for single MRI lesions (negative second-look sonography) categorised as BI-RADS 4 or 5, 4 were cancelled (undetected lesion = 2, technical problems = 2). Twenty-one patients lost to follow-up were excluded.

RESULTS

Twenty-three patients (median age 51 years) were at high risk (BRCA1 = 11, BRCA2 = 7, familial risk = 5), 23 had a suspected local recurrence of breast cancer. Seventy-two imaged lesions (focus = 1, mass enhancement = 32, non-mass-like enhancement = 39) were targeted with a 10-gauge VAB probe using MRI guidance, with a median of 18 specimens per lesion (median procedural time 72 min, range 50-131 min) followed by clip placement. In the case of benignity, MRI follow-up was performed (19 patients, median 389 days, range 33-1,592) or mammography (3 patients, median 420 days, range 372-1,354). According to histopathology results, 29 lesions were benign, 10 were high-risk (papillary = 2, radial scar = 1, atypical epithelial hyperplasia = 7) and 33 malignant (ductal carcinoma in situ = 8, invasive cancers = 25). Three false negative results and 3 complications occurred (1 malaise, 1 skin defect, 1 infection).

CONCLUSION

MRI-guided VAB represents an accurate tool for the histological diagnosis of lesions visible only at MRI.

Breast-conserving surgery using projection and reproduction techniques of surgical-position breast MRI in patients with ductal carcinoma in situ of the breast

BACKGROUND

In this study, we report a breast-conserving surgery (BCS) approach that uses projection and reproduction techniques of breast MRI obtained in the surgical position to the breast surface in patients with ductal carcinoma in situ (DCIS) of the breast.

STUDY DESIGN

Between February 2005 and January 2007, a total of 104 patients with operable breast cancer at our hospital had surgical-position breast MRI examinations. The 24 patients with relatively localized DCIS received BCS using the projection and reproduction techniques of the surgical-position breast MRI. During the same time period, 28 patients with relatively localized DCIS in whom prone-position breast MRI was performed, had conventional BCS using mammography-guided hookwires. In this study, we compared the surgical outcomes of our surgical approach with those of the conventional approach in a total of 52 patients with relatively localized DCIS.

RESULTS

Average volume of the pathologic specimens in the new technique group (27.5 cm(3)) was substantially smaller than that in the conventional BCS group (57.6 cm(3), p = 0.0007). In addition, the positive margin rate was substantially lower in the new technique group (12.5%) than in the conventional BCS group (39.3%; p = 0.029).

CONCLUSIONS

This study demonstrates that BCS can be done guided by the precise projection and reproduction techniques of the lesion obtained by surgical-position breast MRI. To the best of our knowledge, this is the first report of BCS technique for DCIS in this manner. Our surgical approach can be clinically useful in surgical planning and management in patients with DCIS.

The utility of MRI for the screening and staging of breast cancer

INTRODUCTION & BACKGROUND

Contrast-enhanced magnetic resonance imaging (MRI) of the breast has been recently introduced as a potential clinical tool for the detection, diagnosis, staging and management of breast cancer. In this article, we consider the established and evolving roles of MRI with particular reference to screening in high risk women and staging of the primary tumour. Controversies are discussed in the context of the tumour biology and natural history of breast cancer.

METHODS

Articles were identified by searches of PubMed and MEDLINE up to October 2007.

RESULTS

Contrast-enhanced MRI is an effective tool for screening women at high risk of breast cancer. However, randomized trials have yet to demonstrate a reduction in mortality. MRI can also facilitate local staging, in particular, the evaluation of ipsilateral multicentric or multifocal lesions and synchronous contralateral disease which may be 'missed' by conventional imaging. However, efficacy with respect to clinically relevant and patient oriented end-points has yet to be addressed in the context of clinical trials.

CONCLUSIONS

In women at high risk of breast cancer, screening MRI should be used in conjunction with published guidelines. In women with newly diagnosed breast cancer, the utility of MRI is less clearly defined and should be restricted to selected cases within the multidisciplinary setting.

Influence of preoperative MRI on the surgical management of patients with operable breast cancer

PURPOSE

Evaluation of the impact of preoperative magnetic resonance imaging (MRI) of the breast on the clinical management of patients with operable breast cancer (BC).

METHODS

Retrospective analysis of 160 patients with operable breast cancer (stages Tis through T4), treated from 2002 through 2004. All patients underwent a full mammographic assessment, high frequency breast ultrasound, and breast MRI. The impact of preoperative MRI was evaluated for each patient with regard to changes in the therapeutic procedure. Patient and tumor characteristics were analyzed to identify possible patient subgroups that predominantly would benefit from preoperative MRI.

RESULTS

Preoperative MRI affected the clinical management in 44 of 160 patients (27.5%). In 30 cases (18.75%) additional in situ or invasive cancers or a more widespread tumor extent were diagnosed correctly which went undetected by clinical palpation, mammography, and breast ultrasound. In 14 cases (8.75%) additional surgical procedures were performed based on suspicious MRI findings that turned out to be benign in final pathology. Age, menopausal status, breast density, tumor characteristics (type, tumor size, grading), ER-, PR- and HER2-receptor features did not significantly differ between patients in which breast MRI affected the clinical management and patients that experienced no additional information from MRI.

CONCLUSIONS

Preoperative breast MRI changes surgical management of patients with operable breast cancer. MRI detects additional invasive carcinoma and proves to be a powerful supplement to the conventional work-up in the clinical management of breast cancer. This advantage is independent from patients- and tumor-specific characteristics.

Clinicopathologic factors associated with false negative FDG-PET in primary breast cancer

The present study was aimed to determine the clinicopathologic factors that predict false negative (FN) PET results in these patients.

METHODS

A total of 116 breast lesions in 111 patients (pre-menopausal 45; perimenopausal 15; post-menopausal 51) with known or suspicious of breast cancer who underwent FDG-PET scans for staging, were included in this study. The median age was 52+/-11 years (range 32-79 years). All PET studies results were correlated with follow-up surgical pathology results. A cut off value of 2.5 was considered for positive or negative PET results. Univariate and multivariate analyses were performed to identify factors associated with FN results.

RESULTS

Of 116 breast lesions, 85 were malignant and 31 were benign on histopathology. Of the 85 malignant lesions, 41 were true positive (TP) and 44 were FN. Among the 31 benign lesions, 30 were true negative and one was false positive. There was significant difference in the tumor size (p=0.003) and tumor grade (p=0.001) in patients with TP and FN PET results. Multivariate logistic regression demonstrated that tumor size (< or =10 mm) and low tumor grade were independently associated with FN results. No significant relationship of FN PET results was found with age, menopausal status, tumor type, c-erbB-2, estrogen and progesterone receptors, sentinel lymph node or distant metastasis, parenchymal density and multifocality of primary breast tumor.

CONCLUSION

In present study, tumor size and tumor grade are independent factors that predict FDG-PET results. Smaller tumors (< or =10 mm) and low-grade tumors are strong predictor of FN FDG-PET results.

MRI detection of distinct incidental cancer in women with primary breast cancer studied in IBMC 6883

BACKGROUND

Prior single institution studies suggest MRI may improve the assessment of the extent of cancer within the breast, and thus reduce the risk of leaving macroscopic disease in the breast following breast conservation therapy. We report on the rate of MRI and mammography detection of foci of distinct incidental cancer in a prospective, multi center trial involving 426 women with confirmed breast cancer at 15 institutions in the US, Canada, and Germany.

METHODS

Women underwent mammography and MRI prior to biopsy of the suspicious index lesion. Additional incidental lesions (IL) greater than 2 cm from the index lesion that were detected by mammography and MRI were noted and characterized. Biopsy recommendations were associated with ILs given an assessment of suspicious or highly suspicous (BiRads 4 and 5). These assessments were considered a positive test.

RESULTS

MRI had a significantly higher yield of confirmed cancer ILs than mammography (0.18 (95%CI: 0.142-0.214) for MRI versus 0.072 (95%CI: 0.050-0.100) for mammography). The cancer ILs detected by MRI alone appeared to be similar to those detected by mammography with respect to size and histology. The percentage of biopsies of ILs that resulted in a cancer diagnosis was similar between the modalities (MRI 0.72(95%CI: 0.6-0.81); Mammography 0.85 (95%CI: 0.62-0.96)).

CONCLUSIONS

These results suggest that consideration needs to be given regarding the integration of breast MRI into the pretreatment evaluation of women seeking breast conservation therapy.

Rates of reexcision for breast cancer after magnetic resonance imaging-guided bracket wire localization

BACKGROUND

We performed this study to determine rates of close or transected cancer margins after magnetic resonance imaging-guided bracket wire localization for nonpalpable breast lesions.

STUDY DESIGN

Of 243 women undergoing MRI-guided wire localizations, 26 had MRI bracket wire localization to excise either a known cancer (n = 19) or a suspicious MRI-detected lesion (n = 7). We reviewed patient age, preoperative diagnosis, operative intent, mammographic breast density, MRI lesion size, MRI enhancement curve and morphology, MRI Breast Imaging Reporting and Data System (BI-RADS) assessment code, number of bracket wires, and pathology size. We analyzed these findings for their relationship to obtaining clear margins at first operative excision.

RESULTS

Twenty-one of 26 (81%) patients had cancer. Of 21 patients with cancer, 12 (57%) had negative margins at first excision and 9 (43%) had close/transected margins. MRI size > or = 4 cm was associated with a higher reexcision rate (7 of 9, 78%) than those < 4 cm (2 of 12, 17%) (p = 0.009). MRI BI-RADS score, enhancement curve, morphology, and preoperative core biopsy demonstrating ductal carcinoma in situ (DCIS) were not predictive of reexcision. The average number of wires used for bracketing increased with lesion size, but was not associated with improved outcomes. On pathology, cancer size was smaller in patients with negative margins (12 patients, 1.2 cm) than in those with close/transected margins (9 patients, 4.6 cm) (p < 0.001). Reexcision was based on close/transected margins involving DCIS alone (6, 67%), infiltrating ductal carcinoma and DCIS (2, 22%), or infiltrating ductal carcinoma alone (1, 11%). Reexcision pathology demonstrated DCIS (3, 33%), no residual cancer (5, 55%), and 1 patient was lost to followup (1, 11%). Interestingly, cancer patients who required reexcision were younger (p = 0.022), but breast density was not associated with reexcision.

CONCLUSIONS

To our knowledge, this is the first report of MRI-guided bracket wire localization. Patients with MRI-detected lesions less than 4 cm had clear margins at first excision; larger MRI-detected lesions were more likely to have close/transected margins. Reexcision was often because of DCIS and was the only pathology found at reexcision, perhaps because MRI is more sensitive for detecting invasive carcinoma than DCIS.

The role of magnetic resonance imaging in diagnosis and management of breast cancer

A review of the literature on the current applications of breast magnetic resonance imaging (MRI) indications, their rationale and their place in diagnosis and management of breast cancer was given. Contrast-enhanced breast MRI is developing as a valuable adjunct to mammography and sonography. Its high sensitivity for invasive breast cancer establishes its superiority in evaluation of multifocality/multicentricity, tumor response to neoadjuvant chemotherapy, detection of recurrence, and staging. Emerging applications include spectroscopy, usage of new contrast agents, and MRI-guided interventions, including noninvasive treatment of breast cancer. Its potential benefit in screening high-risk women has yet to be established with prospective studies, particularly with regard to false positive results.

Dynamic contrast-enhanced MRI and sonography in patients receiving primary chemotherapy for breast cancer

We compared dynamic contrast-enhanced MRI (DCE-MRI) and sonography (US) for monitoring tumour size in 21 patients with breast cancer undergoing primary chemotherapy (PCT) followed by surgery. The correlation between DCE-MRI and US measurements of tumour size, defined as the product of the two major diameters, was 0.555 (P=0.009), 0.782 (P<0.001), and 0.793 (P<0.001) at baseline, and after two and four cycles of PCT, respectively. The median tumour size was significantly larger when measured by DCE-MRI than by US at baseline (1472 vs 900 mm(2), P<0.001) and after two cycles of PCT (600 vs 400 mm(2), P=0.009). After PCT, the median tumour size measured by the two techniques was similar (256 vs 289 mm(2) for DCE-MRI and US, respectively, P=0.859). The correlation with the histopathological major tumour diameter was 0.824 (P<0.001) and 0.705 (P<0.001) for post-treatment DCE-MRI and US, respectively. Measurements of the final major tumour diameter by DCE-MRI tended to be more precise, including cases achieving a pathological complete response. Randomized trials are warranted to establish the clinical impact of the initial discrepancy in tumour size estimates between DCE-MRI and US, and the trend towards a better definition of the final tumour size provided by DCE-MRI in this clinical setting.

Fluorodeoxyglucose-PET in the management of breast cancer

FDG-PET can be helpful in the diagnosis of primary breast cancer, especially in patients with dense breast tissue, significant fibrocystic changes, fibrosis after radiotherapy, and inconclusive results from MR imaging and other imaging modalities. PET has a limited role in patients with very small tumors and with well-differentiated and lobular types of breast cancer. In preoperative staging, FDG-PET has a low sensitivity for detection of regional lymph node involvement. Also, current PET imaging techniques can easily miss micrometastases. FDG-PET, however, has high positive predictive value for the axillary lymph node involvement, especially patient with advanced tumors. Compared with conventional imaging modalities, FDG-PET provides high diagnostic accuracy in detecting recurrent or metastatic breast carcinoma. FDG-PET seems to be highly useful for monitoring response to therapeutic interventions. This technique can identify response to therapy earlier than any other imaging method currently available. Obviously, identification of nonresponding patients could greatly improve patient management by allowing termination of ineffective and toxic therapies.

The choice of the correct imaging modality in breast cancer management

This brief overview discusses which of the diagnostic options are more reliable and effective for breast cancer imaging with a view to avoiding the unjustified use of techniques that are suboptimal. The technological development of diagnostic imaging has been very impressive, and both radiological (mammography, ultrasonography, computed tomography, magnetic resonance imaging) and nuclear medicine tools (bone scan, planar and SPECT scintigraphy, sentinel node biopsy, positron emission tomography) have helped to overcome past limitations in the detection of small lesions. Furthermore, new approaches have been developed that permit successful differential diagnosis of doubtful lesions and rapid identification of systemic metastases, and allow non-invasive characterisation of the biology of cancer tissue. There is evidence that these advances may have helped in optimising therapeutic strategies. Importantly, the metabolic information provided by nuclear medicine procedures may be combined with the anatomical data supplied by radiological techniques in order to assist in predicting tumour response, planning radiotherapy and monitoring patient outcome. It is difficult to formulate conclusive diagnostic guidelines for application in the work-up of breast cancer, because while the role of some examinations, such as mammography and ultrasonography, is well established, that of others, such as magnetic resonance imaging and positron emission tomography, is still a matter of debate. There is a need for further prospective evaluations with appropriate clinical trials designed to evaluate the impact of these approaches in improving survival and quality of life.