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

Ultrasound diagnosis of non-mass MRI-detected lesions

Magnetic resonance imaging (MRI)-detected lesions are often category 2 or 3 lesions on initial ultrasound examination. In addition, in the case of new non-mass lesions detected on MRI, one would expect to find lesions with ductal dilatation with minimal secretory accumulation, single short lesions with ductal dilatation, cyst-like lesions less than 5 mm in size, mammary gland-like lesions less than 8 mm in size, and very indistinct lesions. Detection is expected to be even more difficult. Currently, there are no clear uniform criteria for the indication of second-look ultrasonography (US) for MRI-detected lesions, so it is not possible to make a general comparison, but recent studies have indicated that the ratio of mass to non-mass MRI-detected lesions is 7:3. And it has been pointed out that the percentage of malignancy is about 30% for each. Before about 2012, the US detection rate was about 70%, and MRI-guided biopsies of undetected lesions showed a small percentage of malignant lesions. Therefore, some observers believe that lesions not detected on US should be followed up, while others believe that MRI-guided biopsy should be performed. Recently, however, the use of surrounding anatomical structures as landmarks for second-look US has increased the detection rate to as high as 87-99%, and the percentage of malignancy remains the same. In addition, recent surveillance of high-risk breast cancer requires careful management of MRI-detected lesions. In this review, we will discuss the literature on MRI-detected lesions and describe ultrasound techniques to accurately detect small lesions and reliably reveal pale lesions based on their structural differences from their surroundings.

Impact of contrast-enhanced mammography in surgical management of breast cancers for women with dense breasts: a dual-center, multi-disciplinary study in Asia

OBJECTIVE

To evaluate the impact of pre-operative contrast-enhanced mammography (CEM) in breast cancer patients with dense breasts.

METHODS

We conducted a retrospective review of 232 histologically proven breast cancers in 200 women (mean age: 53.4 years ± 10.2) who underwent pre-surgical CEM imaging across two Asian institutions (Singapore and Taiwan). Majority (95.5%) of patients had dense breast tissue (BI-RADS category C or D). Surgical decision was recorded in a simulated blinded multi-disciplinary team setting on two separate scenarios: (i) pre-CEM setting with standard imaging, and clinical and histopathological results; and (ii) post-CEM setting with new imaging and corresponding histological findings from CEM. Alterations in surgical plan (if any) because of CEM imaging were recorded. Predictors CEM of patients who benefitted from surgical plan alterations were evaluated using logistic regression.

RESULTS

CEM resulted in altered surgical plans in 36 (18%) of 200 patients in this study. CEM discovered clinically significant larger tumor size or extent in 24 (12%) patients and additional tumors in 12 (6%) patients. CEM also detected additional benign/false-positive lesions in 13 (6.5%) of the 200 patients. Significant predictors of patients who benefitted from surgical alterations found on multivariate analysis were pre-CEM surgical decision for upfront breast conservation (OR, 7.7; 95% CI, 1.9-32.1; p = 0.005), architectural distortion on mammograms (OR, 7.6; 95% CI, 1.3-42.9; p = .022), and tumor size of ≥ 1.5 cm (OR, 1.5; 95% CI, 1.0-2.2; p = .034).

CONCLUSION

CEM is an effective imaging technique for pre-surgical planning for Asian breast cancer patients with dense breasts.

KEY POINTS

• CEM significantly altered surgical plans in 18% (nearly 1 in 5) of this Asian study cohort with dense breasts. • Significant patient and imaging predictors for surgical plan alteration include (i) patients considered for upfront breast-conserving surgery; (ii) architectural distortion lesions; and (iii) tumor size of ≥ 1.5 cm. • Additional false-positive/benign lesions detected through CEM were uncommon, affecting only 6.5% of the study cohort.

Tips for finding magnetic resonance imaging-detected suspicious breast lesions using second-look ultrasonography: a pictorial essay

Second-look ultrasonography (US) is a targeted breast US examination that evaluates suspicious lesions detected on magnetic resonance imaging (MRI). It is a useful tool for determining the probability of malignancy and facilitating US-guided biopsy. Lesions detected on MRI and US should be correlated accurately, which is challenging in some cases. This article documents second-look US and MRI findings that are correlated with the pathology, and suggests helpful approaches for correlating between the two modalities.

Toward Computer-Assisted Triaging of Magnetic Resonance Imaging-Guided Biopsy in Preoperative Breast Cancer Patients

OBJECTIVES

Incidental MR-detected breast lesions (ie, additional lesions to the index cancer) pose challenges in the preoperative workup of patients with early breast cancer. We pursue computer-assisted triaging of magnetic resonance imaging (MRI)-guided breast biopsy of additional lesions at high specificity.

MATERIALS AND METHODS

We investigated 316 consecutive female patients (aged 26 to 76 years; mean, 54 years) with early breast cancer who received preoperative multiparametric breast MRI between 2013 and 2016. In total, 82 (26%) of 316 patients had additional breast lesions on MRI. These 82 patients had 101 additional lesions in total, 51 were benign and 50 were malignant. We collected 4 clinical features and 46 MRI radiomic features from T1-weighted dynamic contrast-enhanced imaging, high-temporal-resolution dynamic contrast-enhanced imaging, T2-weighted imaging, and diffusion-weighted imaging. A multiparametric computer-aided diagnosis (CAD) model using 10-fold cross-validated ridge regression was constructed. The sensitivities were calculated at operating points corresponding to 98%, 95%, and 90% specificity. The model calibration performance was evaluated by calibration plot analysis and goodness-of-fit tests. The model was tested in an independent testing cohort of 187 consecutive patients from 2017 and 2018 (aged 35 to 76 years; mean, 59 years). In this testing cohort, 45 (24%) of 187 patients had 55 additional breast lesions in total, 23 were benign and 32 were malignant.

RESULTS

The multiparametric CAD model correctly identified 48% of the malignant additional lesions with a specificity of 98%. At specificity 95% and 90%, the sensitivity was 62% and 72%, respectively. Calibration plot analysis and goodness-of-fit tests indicated that the model was well fitted.In the independent testing cohort, the specificity was 96% and the sensitivity 44% at the 98% specificity operating point of the training set. At operating points 95% and 90%, the specificity was 83% at 69% sensitivity and the specificity was 78% at 81% sensitivity, respectively.

CONCLUSIONS

The multiparametric CAD model showed potential to identify malignant disease extension with near-perfect specificity in approximately half the population of preoperative patients originally indicated for a breast biopsy. In the other half, patients would still proceed to MRI-guided biopsy to confirm absence of malignant disease. These findings demonstrate the potential to triage MRI-guided breast biopsy.

Automatic extraction of imaging observation and assessment categories from breast magnetic resonance imaging reports with natural language processing

Background:

Structured reports are not widely used and thus most reports exist in the form of free text. The process of data extraction by experts is time-consuming and error-prone, whereas data extraction by natural language processing (NLP) is a potential solution that could improve diagnosis efficiency and accuracy. The purpose of this study was to evaluate an NLP program that determines American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) descriptors and final assessment categories from breast magnetic resonance imaging (MRI) reports.

Methods:

This cross-sectional study involved 2330 breast MRI reports in the electronic medical record from 2009 to 2017. We used 1635 reports for the creation of a revised BI-RADS MRI lexicon and synonyms lists as well as the iterative development of an NLP system. The remaining 695 reports that were not used for developing the system were used as an independent test set for the final evaluation of the NLP system. The recall and precision of an NLP algorithm to detect the revised BI-RADS MRI descriptors and BI-RADS categories from the free-text reports were evaluated against a standard reference of manual human review.

Results:

There was a high level of agreement between two manual reviewers, with a κ value of 0.95. For all breast imaging reports, the NLP algorithm demonstrated a recall of 78.5% and a precision of 86.1% for correct identification of the revised BI-RADS MRI descriptors and the BI-RADS categories. NLP generated the total results in <1 s, whereas the manual reviewers averaged 3.38 and 3.23 min per report, respectively.

Conclusions:

The NLP algorithm demonstrates high recall and precision for information extraction from free-text reports. This approach will help to narrow the gap between unstructured report text and structured data, which is needed in decision support and other applications.

The implementation of natural language processing to extract index lesions from breast magnetic resonance imaging reports

BACKGROUND

There are often multiple lesions in breast magnetic resonance imaging (MRI) reports and radiologists usually focus on describing the index lesion that is most crucial to clinicians in determining the management and prognosis of patients. Natural language processing (NLP) has been used for information extraction from mammography reports. However, few studies have investigated NLP in breast MRI data based on free-form text. The objective of the current study was to assess the validity of our NLP program to accurately extract index lesions and their corresponding imaging features from free-form text of breast MRI reports.

METHODS

This cross-sectional study examined 1633 free-form text reports of breast MRIs from 2014 to 2017. First, the NLP system was used to extract 9 features from all the lesions in the reports according to the Breast Imaging Reporting and Data System (BI-RADS) descriptors. Second, the index lesion was defined as the lesion with the largest number of imaging features. Third, we extracted the values of each imaging feature and the BI-RADS category from each index lesion. To evaluate the accuracy of our system, 478 reports were manually reviewed by two individuals. The time taken to extract data by NLP was compared with that by reviewers.

RESULTS

The NLP system extracted 889 lesions from 478 reports. The mean number of imaging features per lesion was 6.5 ± 2.1 (range: 3-9; 95% CI: 6.362-6.638). The mean number of imaging features per index lesion was 8.0 ± 1.1 (range: 5-9; 95% CI: 7.901-8.099). The NLP system demonstrated a recall of 100.0% and a precision of 99.6% for correct identification of the index lesion. The recall and precision of NLP to correctly extract the value of imaging features from the index lesions were 91.0 and 92.6%, respectively. The recall and precision for the correct identification of the BI-RADS categories were 96.6 and 94.8%, respectively. NLP generated the total results in less than 1 s, whereas the manual reviewers averaged 4.47 min and 4.56 min per report.

CONCLUSIONS

Our NLP method successfully extracted the index lesion and its corresponding information from free-form text.

Assessment of MRI-detected lesions on screening tomosynthesis in patients with newly diagnosed breast cancer

OBJECTIVES

The purpose of this study is to retrospectively evaluate the presence of screening digital breast tomosynthesis (DBT) correlates for suspicious lesions detected on pre-operative staging magnetic resonance imaging (MRI) in patients with newly diagnosed breast cancer.

METHODS

After approval from the institutional review board (IRB), screening DBTs on breast cancer patients with BI-RADS 4 or 5 staging MRI exams between 8/1/17 and 8/1/18 were assessed for presence of DBT correlates for suspicious MRI findings. The pathology of the index lesion, type of additional MRI finding (mass, non-mass enhancement, or focus), correlative finding on tomosynthesis (mass, asymmetry/focal asymmetry, distortion, or calcifications), size on MRI and tomosynthesis, breast density, and pathology of the additional lesion were recorded. The chi-square test of association was used unless otherwise specified. Confidence intervals for proportions were estimated using the Wilson's score method.

RESULTS

17/70 (24%) of additional lesions seen on pre-operative MRI exams in patients with newly diagnosed cancer had a mammographic correlate on corresponding screening DBT. There was no significant relationship between the presence of a mammographic correlate and the type of MRI finding (mass, NME, or focus), breast density, size of lesion, pathology of index cancer, or pathology of the additional lesion (p≥ 0.05).

CONCLUSIONS

76% of additional lesions seen on pre-operative staging MRI in patients with newly diagnosed breast cancer are not seen retrospectively on screening DBT. Since about 24% of MRI-detected additional lesions may have a DBT correlate, DBT exams should be reviewed in patients recalled for further workup of findings seen on pre-operative MRI since this may facilitate DBT-guided biopsy of suspicious lesions, which is preferable to MRI-guided biopsy for cost and patient comfort reasons.

Usefulness of second-look ultrasonography using anatomical breast structures as indicators for magnetic resonance imaging-detected breast abnormalities

Background

Second-look ultrasonography (US) is commonly performed for breast lesions detected using magnetic resonance imaging (MRI), but the identification rate of these lesions remains low. We investigated if US methods using anatomical breast structures can improve the lesion identification rate of MR-detected lesions and evaluated the diagnostic performance of fine-needle aspiration cytology (FNAC) of the second-look US using the above-mentioned method.

Methods

We retrospectively assessed 235 breast lesions (hereinafter, “targets”) subjected to second-look US following MRI between January 2013 and September 2015. US was employed using the conventional methods, and this assessment measured the positional relationships of lesions with regard to surrounding anatomical breast structures (glandular pattern, Cooper’s ligaments, adipose morphology, and vascular routes). Associations were assessed among the following variables: the MRI findings, target size, identification rate, and main US indicators that led to identifying the target; FNAC results and MRI findings; MRI findings and histopathological findings; and FNAC results and histopathological findings. Moreover, the sensitivity and specificity of FNAC were determined.

Results

The identification rate was 99%. The main US indicators leading to identification were a glandular pattern (28–30% of lesions) and other breast structures (~ 25% of lesions). FNAC was performed for 232 targets with the following results: sensitivity of 85.7%, specificity of 91.6%, PPV of 94.1%, NPV of 92.9%, false-negative rate of 14.3%, false-positive rate of 2.1%, and accuracy of 89.7%.

Conclusions

Second-look US using anatomical breast structures as indicators and US-guided FNAC are useful for refining the diagnosis of suspicious breast lesions detected using MRI.

Impact of Preoperative Breast MR Imaging and MR-guided Surgery on Diagnosis and Surgical Outcome of Women with Invasive Breast Cancer with and without DCIS Component

Purpose To (a) compare the diagnostic accuracy of breast magnetic resonance (MR) imaging with that of conventional imaging (digital mammography and breast ultrasonography) in the identification of ductal carcinoma in situ (DCIS) components of biopsy-proven invasive breast cancer before surgery and (b) investigate the surgical outcome (positive margin rates and mastectomy rates) of women with breast cancer who underwent preoperative MR imaging combined with MR-guided needle biopsy and/or MR-guided lesion localization or bracketing where appropriate. Materials and Methods The authors performed a prospective two-center study of 593 consecutive patients with biopsy-proven invasive breast cancer who underwent breast MR imaging in addition to conventional imaging. MR-guided vacuum biopsy and MR-guided lesion bracketing were performed for DCIS components visible at MR imaging alone. The accuracy of breast MR imaging was compared with that of conventional imaging, and surgical outcomes (positive margin and mastectomy rates) were investigated. Results Surgical-pathologic assessment demonstrated DCIS components in 139 of the 593 women (23.4%). The sensitivity of MR imaging for the diagnosis of DCIS components pre-operatively (84.9%; 118 of 139) was significantly higher than that of conventional imaging (36.7%; 51 of 139) (P < .0001); more than half of DCIS components (51.1%; 71 of 139) were detected only with MR imaging. The sensitivity advantage of MR imaging over conventional imaging increased with increasing relative size of DCIS components, as follows: The sensitivity of MR imaging versus conventional imaging for small, marginal DCIS components was 56.8% (21 of 37) versus 29.7% (11 of 37); the sensitivity for extensive DCIS components was 91.7% (55 of 60) versus 41.7% (25 of 60); the sensitivity for large, predominant DCIS components was 100.0% (42 of 42) versus 35.7% (15 of 42). Moreover, the sensitivity advantage of MR imaging over conventional imaging increased with increasing nuclear grade of DCIS components, as follows: The sensitivity of MR imaging versus conventional imaging for low-grade DCIS components was 74.0% (20 of 27) versus 40.7% (11 of 27); the sensitivity for intermediate-grade DCIS components was 84.1% (53 of 63) versus 34.9% (22 of 63); the sensitivity for high-grade DCIS components was 91.8% (45 of 49) versus 36.7% (18 of 49) (P < .05-.001 for all). Positive margin rates were low overall (3.7% [95% Clopper Pearson confidence interval [CI]: 2.3%, 5.6%]) and did not differ significantly between the 139 women with DCIS components (5.0% [95% CI: 2.0%, 10.1%]) compared with the 454 women without such components (3.3% [95% CI: 1.9%, 5.4%]). The same was true for mastectomy rates (10.8% [95% CI: 6.2%, 17.2%] vs 8.1% [95% CI: 5.8%, 11.1%]). Conclusion Breast MR imaging improves depiction of DCIS components of invasive breast cancers before surgery and is associated with positive margin and mastectomy rates that are low irrespective of the presence or absence of DCIS components. ^© RSNA, 2017.

The Changing World of Breast Cancer: A Radiologist's Perspective

Compared with other fields of medicine, there is hardly an area that has seen such fast development as the world of breast cancer. Indeed, the way we treat breast cancer has changed fundamentally over the past decades. Breast imaging has always been an integral part of this change, and it undergoes constant adjustment to new ways of thinking. This relates not only to the technical tools we use for diagnosing breast cancer but also to the way diagnostic information is used to guide treatment. There is a constant change of concepts for and attitudes toward breast cancer, and a constant flux of new ideas, new treatment approaches, and new insights into the molecular and biological behavior of this disease. Clinical breast radiologists and even more so, clinician scientists, interested in breast imaging need to keep abreast with this rapidly changing world. Diagnostic or treatment approaches that are considered useful today may be abandoned tomorrow. Approaches that seem irrelevant or far too extravagant today may prove clinically useful and adequate next year. Radiologists must constantly question what they do, and align their clinical aims and research objectives with the changing needs of contemporary breast oncology. Moreover, knowledge about the past helps better understand present debates and controversies. Accordingly, in this article, we provide an overview on the evolution of breast imaging and breast cancer treatment, describe current areas of research, and offer an outlook regarding the years to come.

Impact of value based breast cancer care pathway implementation on pre-operative breast magnetic resonance imaging utilization

BACKGROUND

Bilateral breast magnetic resonance imaging (MRI) is commonly used in the diagnostic workup of breast cancer (BC) to assess extent of disease and identify occult foci of disease. However, evidence for routine use of pre-operative MRI is lacking. Breast MRI is costly and can lead to unnecessary tests and treatment delays. Clinical care pathways (care paths) are value-based guidelines, which define management recommendations derived by expert consensus and available evidence based data. At Cleveland Clinic, care paths created for newly diagnosed BC patients recommend selective use of pre-operative MRI. We evaluated the number of pre-operative MRIs ordered before and after implementing an institution wide BC care paths in April 2014.

METHODS

A retrospective review was conducted of BC cases during the years 2012, 2014, and part of 2015. Patient, tumor and treatment characteristics were collected. Pre-operative MRI utilization was compared before and after care path implementation.

RESULTS

We identified 1,515 BC patients during the study period. Patients were more likely to undergo pre-operative MRI in 2012 than 2014 (OR: 2.77; P<0.001; 95% CI: 1.94-3.94) or 2015 (OR: 4.14; P<0.001; 95% CI: 2.51-6.83). There was a significant decrease in pre-operative MRI utilization between 2012 and 2014 (P<0.001) after adjustment for pre-operative MRIs ordered for care path indications.

CONCLUSIONS

Implementation of online BC care paths at our institution was associated with a decreased use of pre-operative MRI overall and in patients without a BC care path indication, driving value based care through the reduction of pre-operative breast MRIs.

Contrast-enhanced spectral mammography vs. mammography and MRI - clinical performance in a multi-reader evaluation

OBJECTIVES

To compare the diagnostic performance of contrast-enhanced spectral mammography (CESM) to digital mammography (MG) and magnetic resonance imaging (MRI) in a prospective two-centre, multi-reader study.

METHODS

One hundred seventy-eight women (mean age 53 years) with invasive breast cancer and/or DCIS were included after ethics board approval. MG, CESM and CESM + MG were evaluated by three blinded radiologists based on amended ACR BI-RADS criteria. MRI was assessed by another group of three readers. Receiver-operating characteristic (ROC) curves were compared. Size measurements for the 70 lesions detected by all readers in each modality were correlated with pathology.

RESULTS

Reading results for 604 lesions were available (273 malignant, 4 high-risk, 327 benign). The area under the ROC curve was significantly larger for CESM alone (0.84) and CESM + MG (0.83) compared to MG (0.76) (largest advantage in dense breasts) while it was not significantly different from MRI (0.85). Pearson correlation coefficients for size comparison were 0.61 for MG, 0.69 for CESM, 0.70 for CESM + MG and 0.79 for MRI.

CONCLUSIONS

This study showed that CESM, alone and in combination with MG, is as accurate as MRI but is superior to MG for lesion detection. Patients with dense breasts benefitted most from CESM with the smallest additional dose compared to MG.

KEY POINTS

• CESM has comparable diagnostic performance (ROC-AUC) to MRI for breast cancer diagnostics. • CESM in combination with MG does not improve diagnostic performance. • CESM has lower sensitivity but higher specificity than MRI. • Sensitivity differences are more pronounced in dense and not significant in non-dense breasts. • CESM and MRI are significantly superior to MG, particularly in dense breasts.

The Changing World of Breast Cancer: A Radiologist's Perspective

Compared with other fields of medicine, there is hardly an area that has seen such fast development as the world of breast cancer. Indeed, the way we treat breast cancer has changed fundamentally over the past decades. Breast imaging has always been an integral part of this change, and it undergoes constant adjustment to new ways of thinking. This relates not only to the technical tools we use for diagnosing breast cancer but also to the way diagnostic information is used to guide treatment. There is a constant change of concepts for and attitudes toward breast cancer, and a constant flux of new ideas, new treatment approaches, and new insights into the molecular and biological behavior of this disease. Clinical breast radiologists and even more so, clinician scientists, interested in breast imaging need to keep abreast with this rapidly changing world. Diagnostic or treatment approaches that are considered useful today may be abandoned tomorrow. Approaches that seem irrelevant or far too extravagant today may prove clinically useful and adequate next year. Radiologists must constantly question what they do, and align their clinical aims and research objectives with the changing needs of contemporary breast oncology. Moreover, knowledge about the past helps better understand present debates and controversies. Accordingly, in this article, we provide an overview on the evolution of breast imaging and breast cancer treatment, describe current areas of research, and offer an outlook regarding the years to come.

Who may benefit from preoperative breast MRI? A single-center analysis of 1102 consecutive patients with primary breast cancer

Several authors question the potential benefit of preoperative magnetic resonance imaging (MRI) against the background of possible overdiagnosis, false-positive findings, and unnecessary resections in patients with newly diagnosed breast cancer. In order to reveal a better selection of patients who should undergo preoperative MRI after histological confirmed breast cancer, the present analysis was implemented. We aimed to evaluate the influence of preoperative breast MRI in patients with newly diagnosed breast cancer to find subgroups of patients that are most likely to benefit from preoperative MRI by the detection of occult malignant foci. A total of 1102 consecutive patients who underwent treatment for primary breast cancer between 2002 and 2013 were retrospectively analyzed. All patients underwent triple assessment by breast ultrasound, mammography, and bilateral breast MRI. MRI findings not seen on conventional imaging that suggested additional malignant disease was found in 344 cases (31.2 %). Histological confirmed malignant foci were found in 223 patients (20.2 %) within the index breast and in 28 patients (2.5 %) in the contralateral breast. The rate of false-negative biopsies was 31 (2.8 %) and 62 (5.6 %), respectively. Premenopausal women (p = 0.024), lobular invasive breast cancer (p = 0.02) as well as patients with high breast density [American College of Radiology (ACR) 3 + 4; p = 0.01] were significantly associated with additional malignant foci in the index breast. Multivariate analysis confirmed lobular histology (p = 0.041) as well as the co-factors "premenopausal stage" and "high breast density (ACR 3+4)" (p = 0.044) to be independently significant. Previous studies revealed that breast MRI is a reliable tool for predicting tumor extension as well as for the detection of additional ipsilateral and contralateral tumor foci in histological confirmed breast cancer. In the present study, we demonstrate that especially premenopausal patients with high breast density as well as patients with lobular histology seem to profit from preoperative MRI.

Realization of a biomechanical model-assisted image guidance system for breast cancer surgery using supine MRI

PURPOSE

Unfortunately, the current re-excision rates for breast conserving surgeries due to positive margins average 20-40 %. The high re-excision rates arise from difficulty in localizing tumor boundaries intraoperatively and lack of real-time information on the presence of residual disease. The work presented here introduces the use of supine magnetic resonance (MR) images, digitization technology, and biomechanical models to investigate the capability of using an image guidance system to localize tumors intraoperatively.

METHODS

Preoperative supine MR images were used to create patient-specific biomechanical models of the breast tissue, chest wall, and tumor. In a mock intraoperative setup, a laser range scanner was used to digitize the breast surface and tracked ultrasound was used to digitize the chest wall and tumor. Rigid registration combined with a novel nonrigid registration routine was used to align the preoperative and intraoperative patient breast and tumor. The registration framework is driven by breast surface data (laser range scan of visible surface), ultrasound chest wall surface, and MR-visible fiducials. Tumor localizations by tracked ultrasound were only used to evaluate the fidelity of aligning preoperative MR tumor contours to physical patient space. The use of tracked ultrasound to digitize subsurface features to constrain our nonrigid registration approach and to assess the fidelity of our framework makes this work unique. Two patient subjects were analyzed as a preliminary investigation toward the realization of this supine image-guided approach.

RESULTS

An initial rigid registration was performed using adhesive MR-visible fiducial markers for two patients scheduled for a lumpectomy. For patient 1, the rigid registration resulted in a root-mean-square fiducial registration error (FRE) of 7.5 mm and the difference between the intraoperative tumor centroid as visualized with tracked ultrasound imaging and the registered preoperative MR counterpart was 6.5 mm. Nonrigid correction resulted in a decrease in FRE to 2.9 mm and tumor centroid difference to 5.5 mm. For patient 2, rigid registration resulted in a FRE of 8.8 mm and a 3D tumor centroid difference of 12.5 mm. Following nonrigid correction for patient 2, the FRE was reduced to 7.4 mm and the 3D tumor centroid difference was reduced to 5.3 mm.

CONCLUSION

Using our prototype image-guided surgery platform, we were able to align intraoperative data with preoperative patient-specific models with clinically relevant accuracy; i.e., tumor centroid localizations of approximately 5.3-5.5 mm.

Preoperative MRI in patients with locoregional recurrent breast cancer: influence on treatment modalities

RATIONALE AND OBJECTIVES

The purpose of this analysis was to evaluate the impact of preoperative magnetic resonance imaging (MRI) on management in patients with locoregional recurrent breast cancer.

MATERIALS AND METHODS

Forty-three patients who underwent treatment for locoregional relapse of breast cancer from 2008 through 2012 were analyzed. All patients underwent both conventional surveillance by mammography, ultrasound, and clinical examination and subsequent bilateral breast MRI.

RESULTS

Preoperative MRI detected additional tumor foci in 15 of 43 patients (34.9%). In two cases (4.7%), the diagnosis of occult sites had no influence on the subsequent treatment. Two patients (4.7%) had an unfavorable change of surgical management with unnecessary additional resection of benign foci. Eleven patients benefited from the MRI scan detecting malignant occult lesions (25.6%) resulting in either additional surgical resection or radiotherapy. Patient and tumor characteristics in primary disease did not differ significantly between patients with a favorable impact on surgical management and patients who experienced either no benefit or even disadvantage from MRI scan.

CONCLUSIONS

Preoperative breast MRI has a strong impact on the management of locoregional recurrent breast cancer. This study demonstrates that breast MRI is a powerful supplement to conventional diagnostic work-up, both during follow-up or preoperative treatment planning in recurrent disease.

Contrast-enhanced spectral mammography: Does mammography provide additional clinical benefits or can some radiation exposure be avoided?

The purpose of this study was to compare contrast-enhanced spectral mammography (CESM) with mammography (MG) and combined CESM + MG in terms of detection and size estimation of histologically proven breast cancers in order to assess the potential to reduce radiation exposure. A total of 118 patients underwent MG and CESM and had final histological results. CESM was performed as a bilateral examination starting 2 min after injection of iodinated contrast medium. Three independent blinded radiologists read the CESM, MG, and CESM + MG images with an interval of at least 4 weeks to avoid case memorization. Sensitivity and size measurement correlation and differences were calculated, average glandular dose (AGD) levels were compared, and breast densities were reported. Fisher's exact and Wilcoxon tests were performed. A total of 107 imaging pairs were available for analysis. Densities were ACR1: 2, ACR2: 45, ACR3: 42, and ACR4: 18. Mean AGD was 1.89 mGy for CESM alone, 1.78 mGy for MG, and 3.67 mGy for the combination. In very dense breasts, AGD of CESM was significantly lower than MG. Sensitivity across readers was 77.9 % for MG alone, 94.7 % for CESM, and 95 % for CESM + MG. Average tumor size measurement error compared to postsurgical pathology was -0.6 mm for MG, +0.6 mm for CESM, and +4.5 mm for CESM + MG (p < 0.001 for CESM + MG vs. both modalities). CESM alone has the same sensitivity and better size assessment as CESM + MG and was significantly better than MG with only 6.2 % increase in AGD. The combination of CESM + MG led to systematic size overestimation. When a CESM examination is planned, additional MG can be avoided, with the possibility of saving up to 61 % of radiation dose, especially in patients with dense breasts.

Where does radioimmunotherapy fit in the management of breast cancer?

Breast cancer is one of the most commonly diagnosed malignancies and is the main cause of death in women aged 40-49 years. Metastatic breast cancer is a heterogeneous disease that has a variety of different clinical presentations, ranging from solitary metastatic lesion to diffuse and multiple organ involvement. The biological heterogeneity of metastatic breast cancer has led to its unpredictable clinical behavior. One of the major challenges, therefore, is to identify predictive and prognostic models facilitating the selection of patients who can benefit from more aggressive and potentially curative options. This article provides an overview of the current management of metastatic breast cancer with focused emphasis on radioimmunotherapy.

Differentiation between benign and malignant breast tumors using kinetic features of real-time harmonic contrast-enhanced ultrasound

BACKGROUND

Contrast-enhanced ultrasound (CEUS) has gained interest because of its ability to gather vascular information in diverse organs. There is still a subject of debate concerning its value in breast lesions, especially as a differential diagnostic tool.

PURPOSE

To investigate whether kinetic parameters of CEUS can differentiate between malignant and benign breast lesions.

MATERIAL AND METHODS

We evaluated 75 malignant and 21 benign lesions in the breast or axilla. Contrast harmonic imaging (CHI) US was performed after the injection of a bolus dose of 2.4 mL of Sono Vue® (Bracco, Milano, Italy). The following parameters were calculated for kinetic analysis: initial slope, time to peak enhancement, wash-out ratios W(21) and W(50) (relative decrease in signal intensity from the peak enhancement to 21 s and 50 s, respectively).

RESULTS

A significant difference was found between the benign and malignant lesions in time-to-peak (P value <0.05) and wash-out ratios W(21) (P value <0.001) and W(50) (P value <0.001). The mean time-to-peak was 9.3 s for malignant and 14.6 s for benign lesions. The mean signal drop from peak to signal intensity measured at 50 s was 85% for malignant and 66% for benign lesions. There was no difference in absolute values of peak signal intensity and initial slope. The most significant difference between standardized benign and malignant wash-out curves was found at 21 s but statistical significance was reached in the range of 14-50 s.

CONCLUSION

Real-time CEUS can evolve into a new non-invasive option for differentiate malignant from benign breast lesions.

[Using magnetic resonance imaging for staging can change the therapeutic management in patients with breast cancer]

OBJECTIVE

To compare two series of patients with breast cancer, one staged using preoperative MRI and the other staged using conventional techniques, analyzing the changes to treatment, the number of mastectomies, and the number of reinterventions due to involvement of the margins.

MATERIAL AND METHODS

We reviewed 600 patients divided into 300 patients with preoperative MRI (series 1) and 300 without preoperative MRI (series 2). We recorded the following variables: age, menopausal status, tumor size on pathological examination, multiplicity and bilaterality, surgical treatment and type of treatment, the administration of neoadjuvant chemotherapy, and reintervention for involved margins. We used Student's t-test and the chi-square test to compare the variables between the two series.

RESULTS

The mean age of patients in the two series was similar (51.5 and 51.8 years, P=0.71). The mean size of the tumor was smaller in series 1 (16.9 mm vs 22.3 mm) (P<.001). More multiple tumors were detected in series 1 (28.7 vs 15.7%) (P<.001). The rate of mastectomies was lower in series 1 (25 vs 48%) (P<.001). Oncoplastic and bilateral surgeries were performed only in series 1. Neoadjuvant chemotherapy was administered more often in series 1 (30.7 vs 9.3%) (P<.001). The difference in the number of reinterventions for involved margins did not reach significance (7.2% in series 1 vs 3.2% in series 2) (P=.095).

CONCLUSION

When MRI was used for staging, neoadjuvant chemotherapy and oncoplastic surgery were used more often and the mastectomy rate decreased. Despite the increase in conservative surgery in patients staged with MRI, the number of reinterventions for involved margins did not increase, although there was a trend towards significance.

Preoperative staging with magnetic resonance imaging, with confirmatory biopsy, improves surgical outcomes in women with breast cancer without increasing rates of mastectomy

Needle biopsy to evaluate findings on MRI that could alter surgical planning has been recommended. This study is a retrospective review to evaluate MRI preoperative staging with biopsy confirmation of suspicious findings. A total of 184 women were diagnosed with breast cancer between January 2004 and June 2008. Of these, 79 underwent bilateral MRI before definitive surgery and 105 did not. Suspicious findings on MRI, mammography, or clinical exam underwent additional needle biopsy at the discretion of the surgeon. A retrospective chart review was performed to compare the two groups with respect to rates of reoperative surgery, successful breast conservation, and confirmatory biopsies. Sensitivity and specificity of MRI for preoperative staging is 0.81 and 0.84, respectively. There were no significant differences in demographics or cancer characteristics between the MRI and non-MRI groups. Fewer women who underwent preoperative MRI staging required repeat breast surgery (11% versus 26%, p = .04) or repeat axillary surgery (10% versus 20%, p = .05). There is no difference in the proportion of women who successfully completed conservative therapy and those treated radically (52% versus 53%), but there is a significant increase in women who undergo additional needle biopsy to confirm suspicious findings after initial diagnosis in the MRI group (25% versus 11% p = .04). In this study, mastectomy rates are not increased; suggesting that women who undergo mastectomy following staging would undergo mastectomy following failed conservative therapy if they were not staged. The downside of this improvement is a 14% increase in women who require confirmatory biopsy.

Yield of Selective Magnetic Resonance Imaging in Preoperative Workup of Newly Diagnosed Breast Cancer Patients Planned for Breast Conserving Surgery

The role of routine preoperative magnetic resonance imaging (MRI) in newly diagnosed breast cancer patients planned for breast conserving surgery is presently being debated. In our medical center we practice selective use of preoperative MRI; we sought to examine the yield of MRI in this highly selected group of patients. A retrospective study of all newly diagnosed breast cancer patients presenting between January 2007 and July 2010 to the Tel Aviv Sourasky Medical Center (Tel Aviv, Israel) was completed. Patients planned for breast conserving surgery who underwent preoperative MRI were included in this study. Patients and tumor characteristics, indication for MRI, findings on MRI, consequent workup, and impact on surgical treatment were recorded. Association between preoperative characteristics and yield of MRI was examined. During the study period, 105 patients that were candidates for breast conserving surgery underwent pre-operative evaluation with MRI. Use of breast MRI increased over time. Rates of mastectomy were stable throughout the study years. Dense mammogram was the most frequent (51, 68%) indication for MRI. Additional suspicious findings were found in 41 (39%) patients, prompting further workup including 36 biopsies in 25 patients, of which 22 (61%) were with cancer. These additional findings prompted a change in the surgical plan in a third of the patients. In most patients (92; 88%) clear margins were achieved. Limiting the use of MRI in the preoperative workup of breast cancer patients to a selected group of patients can increase the yield of MRI.

Clinical outcome of magnetic resonance imaging-detected additional lesions in breast cancer patients

Purpose

The aim of this study was to investigate the clinical outcome of additional breast lesions identified with breast magnetic resonance imaging (MRI) in breast cancer patients.

Methods

A total of 153 patients who underwent breast MRI between July 2006 and March 2008 were retrospectively reviewed. Thirty-three patients (21.6&) were recommended for second-look ultrasound (US) for further characterization of additional lesions detected on breast MRI and these patients constituted our study population.

Results

Assessment for lesions detected on breast MRI consisted of the following: 25 benign lesions (73.5&), two indeterminate (5.9%), and seven malignant (20.6%) in 33 patients. Second-look US identified 12 additional lesions in 34 lesions (35.3%) and these lesions were confirmed by histological examination. Of the 12 lesions found in the 11 patients, six (50.0%) including one contralateral breast cancer were malignant. The surgical plan was altered in 18.2% (six of 33) of the patients. The use of breast MRI justified a change in treatment for four patients (66.7%) and caused two patients (33.3&) to undergo unwarranted additional surgical procedures.

Conclusion

Breast MRI identified additional multifocal or contralateral cancer which was not detected initially on conventional imaging in breast cancer patients. Breast MRI has become an indispensable modality in conjunction with conventional modalities for preoperative evaluation of patients with operable breast cancer.

Role of science in the treatment of breast cancer when tumor multicentricity is present

During the past 100 years, there have been two major controversies with regard to the treatment of primary breast cancer. The first controversy, which occurred approximately 35 years ago, questioned the performance of radical mastectomy, as originally proposed by Halsted in the 1890s. That controversy was resolved by the use of laboratory and clinical research, hypothesis formulation, and evaluation of the efficacy of the latter through the conduct of randomized clinical trials. A second major controversy arose when magnetic resonance imaging began to detect the presence of tumor multicentricity in many breast cancer patients, resulting in a resurgence in mastectomy in women who could have been treated with breast-preserving surgery. Because the use of science resolved the first controversy, I investigated whether there was scientific evidence to justify the current reversion to mastectomy. Extensive examination of the vast amount of recent medical literature related to that subject, that is, individual articles, review articles, and reports from the use of clinical trials, demonstrated that many physicians are not familiar with the scientific method, and thus, were unable to present, in those articles, credible evidence to support mastectomy in the presence of tumor cell multicentricity. Aside from the randomized clinical trial conducted by the National Surgical Adjuvant Breast and Bowel Project begun in 1976, which demonstrated no statistically significant difference in disease-free survival, distant disease-free survival, and overall survival between mastectomy and lumpectomy with or without radiation therapy, there has been no information in any of the few recently conducted studies involving multicentricity to justify the current resurgence in mastectomy.

Breast magnetic resonance imaging: current clinical indications

Breast magnetic resonance (MR) is highly sensitive in the detection of invasive breast malignancies. As technology improves, as interpretations and reporting by radiologists become standardized through the development of guidelines by expert consortiums, and as scientific investigation continues, the indications and uses of breast MR as an adjunct to mammography continue to evolve. This article discusses the current clinical indications for breast MR including screening for breast cancer, diagnostic indications for breast MR, and MR guidance for interventional procedures.

Noninvasive subcellular imaging in breast cancer risk assessment: construction of diagnostic windows

AIM

Breast cancer is the most common cause of cancer-related death among women. Delayed diagnosis leads to development of metastasis and impairs the outcome. This study was designed to utilize subcellular DNA imaging by 'comet assay' and determine pathology-specific comet patterns as the robust biomarker to distinguish between high and low risk for breast cancer development among predisposed individuals with benign breast alterations.

MATERIALS & METHODS

A total of 161 patients were grouped as follows: benignancy, premenopause (n = 59); benignancy, postmenopause (n = 20); breast cancer, premenopause (n = 19); breast cancer, postmenopause (n = 63). On average, 800-1000 comets were evaluated per patient.

RESULTS & CONCLUSION

The qualitative comet assay is an innovative approach for breast cancer risk assessment that can be utilized for the screening of highly predisposed individuals among patients with benign breast alterations. Pathology-specific comet patterns have been identified as the robust biomarker for breast cancer risk. Mathematic model-based diagnostic windows have been constructed for their clinical application.

High cancer yield and positive predictive value: outcomes at a center routinely using preoperative breast MRI for staging

OBJECTIVE

The purpose of our study is to report the outcomes at a center that routinely uses breast MRI for preoperative staging, regardless of lesion histology or patient characteristics.

MATERIALS AND METHODS

Five hundred ninety-two patients with recently diagnosed breast cancer who underwent staging with preoperative breast MRI between January 1, 2003, and April 30, 2007, were reviewed. Five hundred seventy patients comprised the analysis set. Patient age, breast density, index tumor histology, receptor status (ER, PR, and HER2), and lymph node status were recorded. Biopsy rates, positive predictive values (PPVs) of biopsy, and overall cancer yield were calculated and compared using the chi-square test across patient age, mammographic breast density, index tumor type, receptor status, and lymph node status.

RESULTS

Biopsy was recommended and performed for 152 of 570 (27%) patients found to have one or more suspicious lesions on MRI distinct from the index cancer. Sixty-seven of 152 women who underwent biopsy had additional cancers diagnosed, for a PPV of 44%. Overall, 12% (67/570) of women had otherwise occult cancers diagnosed by MRI, with 8% having additional sites or greater extent of ipsilateral disease and 4% having unsuspected contralateral cancer detected by MRI alone. No significant differences were found in the probability of detecting an occult cancer on the basis of patient age, breast density, index tumor characteristics, or lymph node status.

CONCLUSION

Breast MRI detects otherwise occult cancer with an overall added cancer yield of 12% and a high PPV of 44% when applied to a diverse population of patients with newly diagnosed breast cancer.

Role of magnetic resonance imaging in evaluating the extent of disease

Preoperative breast imaging evaluation can contribute useful clinical information to the management of the patient with known breast cancer. Breast magnetic resonance imaging (MRI) has been used as part of this imaging evaluation, and the ability of breast MRI to detect otherwise occult multifocal and multicentric disease has been demonstrated in multiple studies. The use of MRI for breast cancer staging remains under debate, however. This article reviews some of the current discussion regarding the use of breast MRI in this patient population. It is important to note that this discussion occurs in an evolving context of surgical and breast conservation therapies.

Breast cancers not detected at MRI: review of false-negative lesions

OBJECTIVE

The objective of our study was to determine the sensitivity of cancer detection at breast MRI using current imaging techniques and to evaluate the characteristics of lesions with false-negative examinations.

MATERIALS AND METHODS

Two hundred seventeen patients with 222 newly diagnosed breast cancers or highly suspicious breast lesions that were subsequently shown to be malignant underwent breast MRI examinations for staging. Two breast imaging radiologists performed a consensus review of the breast MRI examinations. The absence of perceptible contrast enhancement at the expected site was considered to be a false-negative MRI. Histology of all lesions was reviewed by an experienced breast pathologist.

RESULTS

Enhancement was observed in 213 (95.9%) of the 222 cancer lesions. Of the nine lesions without visible enhancement, two lesions were excluded because the entire tumor had been excised at percutaneous biopsy performed before the MRI examination and no residual tumor was noted on the final histology. The overall sensitivity of MRI for the known cancers was 96.8% (213/220); for invasive cancer, 98.3% (176/179); and for ductal carcinoma in situ, 90.2% (37/41).

CONCLUSION

In a population of 220 sequentially diagnosed breast cancer lesions, we found seven (3.2%) MRI-occult cancers, fewer than seen in other published studies. Small tumor size and diffuse parenchymal enhancement were the principal reasons for these false-negative results. Although the overall sensitivity of cancer detection was high (96.8%), it should be emphasized that a negative MRI should not influence the management of a lesion that appears to be of concern on physical examination or on other imaging techniques.

Magnetic resonance imaging of the breast: recommendations from the EUSOMA working group

The use of breast magnetic resonance imaging (MRI) is rapidly increasing. EUSOMA organised a workshop in Milan on 20-21st October 2008 to evaluate the evidence currently available on clinical value and indications for breast MRI. Twenty-three experts from the disciplines involved in breast disease management - including epidemiologists, geneticists, oncologists, radiologists, radiation oncologists, and surgeons - discussed the evidence for the use of this technology in plenary and focused sessions. This paper presents the consensus reached by this working group. General recommendations, technical requirements, methodology, and interpretation were firstly considered. For the following ten indications, an overview of the evidence, a list of recommendations, and a number of research issues were defined: staging before treatment planning; screening of high-risk women; evaluation of response to neoadjuvant chemotherapy; patients with breast augmentation or reconstruction; occult primary breast cancer; breast cancer recurrence; nipple discharge; characterisation of equivocal findings at conventional imaging; inflammatory breast cancer; and male breast. The working group strongly suggests that all breast cancer specialists cooperate for an optimal clinical use of this emerging technology and for future research, focusing on patient outcome as primary end-point.