Multicenter comparative multimodality surveillance of women at genetic-familial high risk for breast cancer (HIBCRIT study): interim results

Preoperative breast magnetic resonance imaging: applications in clinical practice

Results of large randomized trials have shown that survival rates after breast conserving surgery are equivalent to those obtained by radical mastectomy. Breast conserving surgery with wide local excision in women with early stage breast cancer who are thought to have a single and resectable tumour as determined by clinical examination and conventional imaging followed by postoperative irradiation is the standard of care in early breast cancer. Mapping of local disease is the key element to guide optimal surgery to obtain tumour-free margins, thereby decreasing risk of local recurrence. The usual preoperative workup of breast malignancy consists of clinical breast examination and mammography with or without ultrasound. However, mammography and ultrasound fail to accurately assess tumour extent in as many as a third of patients eligible for breast conserving therapy. It is well established that magnetic resonance imaging is far superior to mammography (with and without ultrasound) for mapping the local extent of breast cancer. Experts advocate its use despite its high costs, high number of false positive findings, and lack of evidence from randomized prospective trials and, notably, fear of "overtreatment." This article discusses the current role of breast magnetic resonance imaging with its clinical advantages and applications.

Effect of protocol parameters on contrast agent washout curve separability in breast dynamic contrast enhanced MRI: a simulation study

Variability in diagnostic performance of breast dynamic contrast-enhanced MRI has highlighted the need for improved standardization. While guidance exists on some aspects of the technique, currently, there is no standardized method for selecting repetition time and flip angle, which are important determinants of image contrast. This study develops a theoretical framework for quantitative optimization of temporal aspects of dynamic contrast-enhanced MRI based on area under the receiver operating curve. Optimizations in simulation demonstrate the potential for increases in area under the receiver operating characteristic curve by up to 0.20 and specificity at a sensitivity of 90% by up to 19%, depending on the protocol. These results suggest that careful selection of repetition time and flip angle can improve diagnostic performance and identify these quantities as potentially important parameters for future standardization.

Statistical comparison of dynamic contrast-enhanced MRI pharmacokinetic models in human breast cancer

By fitting dynamic contrast-enhanced MRI data to an appropriate pharmacokinetic model, quantitative physiological parameters can be estimated. In this study, we compare four different models by applying four statistical measures to assess their ability to describe dynamic contrast-enhanced MRI data obtained in 28 human breast cancer patient sets: the chi-square test (χ(2)), Durbin-Watson statistic, Akaike information criterion, and Bayesian information criterion. The pharmacokinetic models include the fast exchange limit model with (FXL_v(p)) and without (FXL) a plasma component, and the fast and slow exchange regime models (FXR and SXR, respectively). The results show that the FXL_v(p) and FXR models yielded the smallest χ(2) in 45.64 and 47.53% of the voxels, respectively; they also had the smallest number of voxels showing serial correlation with 0.71 and 2.33%, respectively. The Akaike information criterion indicated that the FXL_v(p) and FXR models were preferred in 42.84 and 46.59% of the voxels, respectively. The Bayesian information criterion also indicated the FXL_v(p) and FXR models were preferred in 39.39 and 45.25% of the voxels, respectively. Thus, these four metrics indicate that the FXL_v(p) and the FXR models provide the most complete statistical description of dynamic contrast-enhanced MRI time courses for the patients selected in this study.

Magnetic resonance imaging of the breast for cancer diagnosis and staging

Gadolinium-enhanced breast magnetic resonance imaging (MRI) is optimally suited for the diagnosis and assessment of breast cancer. The complete breast MRI examination, which includes select nonenhanced sequences, yields abundant information about the nature and stage of disease. In this article, we will explore cancer diagnosis by examining the main imaging features of breast malignancy as well as the assessment of surrounding structures. We will then discuss current ideas in the use of breast MRI in breast cancer, including high-risk screening, evaluation of extent of disease, role in surgical planning, and the use of MRI in the patient receiving neoadjuvant chemotherapy. Breast MRI plays an important role in the assessment of patients with breast malignancy-a role that is yet to be fully defined and used. By understanding the strengths and weakness of this imaging method in cancer evaluation, we hope to highlight the appropriate uses of the technique.

The evolving role of new imaging methods in breast screening

The potential to avert breast cancer deaths through screening means that efforts continue to identify methods which may enhance early detection. While the role of most new imaging technologies remains in adjunct screening or in the work-up of mammography-detected abnormalities, some of the new breast imaging tests (such as MRI) have roles in screening groups of women defined by increased cancer risk. This paper highlights the evidence and the current role of new breast imaging technologies in screening, focusing on those that have broader application in population screening, including digital mammography, breast ultrasound in women with dense breasts, and computer-aided detection. It highlights that evidence on new imaging in screening comes mostly from non-randomised studies that have quantified test detection capability as adjunct to mammography, or have compared measures of screening performance for new technologies with that of conventional mammography. Two RCTs have provided high-quality evidence on the equivalence of digital and conventional mammography and on outcomes of screen-reading complemented by CAD. Many of these imaging technologies enhance cancer detection but also increase recall and false positives in screening.

Investigating the limit of detectability of a positron emission mammography device: a phantom study

PURPOSE

A new positron emission mammography (PEM) device (PEM Flex Solo II, Naviscan Inc., San Diego, CA) has recently been introduced and its performance characteristics have been documented. However, no systematic assessment of its limit of detectability has been evaluated. The aim of this work is to investigate the limit of detectability of this new PEM system using a novel, customized breast phantom.

METHODS

Two sets of F-18 infused gelatin breast phantoms of varying thicknesses (2, 4, 6, and 8 cm) were constructed with and without (blank) small, shell-less contrast objects (2 mm thick disks) of varying diameters (3-14.5 mm) [volumes: 0.15-3.3 cc] and activity concentration to background ratio (ACR) (2.7-58). For the phantom set with contrast objects, the disks were placed centrally inside the phantoms and both phantom sets were imaged for a period of 10 min on the PEM device. In addition, scans for the 2 and 6 cm phantoms were repeated at different times (0, 90, and 150 min) post phantom construction to evaluate the impact of total activity concentration (count density) on lesion detectability. Each object from each phantom scan was then segmented and placed randomly in a corresponding blank phantom image. The resulting individual images were presented blindly to seven physician observers (two nuclear medicine and five breast imaging radiologists) and scored in a binary fashion (1-correctly identified object, 0-incorrect). The sensitivity, specificity, and accuracy of lesion detectability were calculated and plots of sensitivity versus ACR and lesion diameters for different phantom thicknesses and count density were generated.

RESULTS

The overall (mean) detection sensitivity across all variables was 0.68 (95% CI: [0.64, 0.72]) with a corresponding specificity of 0.93 [0.87, 0.98], and diagnostic accuracy of 0.72 [0.70, 0.75]. The smallest detectable object varied strongly as a function of ACR, as sensitivity ranged from 0.36 [0.29, 0.44] for the smallest lesion size (3 mm) to 0.80 [0.75, 0.84] for the largest (14.5 mm).

CONCLUSIONS

The detectability performance of this PEM system demonstrated its ability to resolve small objects with low activity concentration ratios which may assist in the identification of early stage breast cancer. The results of this investigation can be used to correlate lesion detectability with tumor size, ACR, count rate, and breast thickness.

Update on screening breast MRI in high-risk women

Breast cancer is the most common cancer in women. One in 8 women develops breast cancer and approximately 30% of all affected women die of the disease. By performing a nationwide screening program in the Netherlands, a mortality reduction of 1.2% annually was achieved. The screening program is for women between the ages of 50 and 75 years; however, women with an increased risk for developing breast cancer are mostly younger. The role of MRI in this particular group of women has been described in different studies. MRI of the breast in this group of women has a higher sensitivity than mammography, but the highest sensitivity is reached by the combination of these two imaging modalities.

Comparison of costs and benefits of breast cancer screening with mammography, ultrasonography, and MRI

Screening mammography performed annually on all women beginning at age 40 years has reduced breast cancer deaths by 30% to 50%. The cost per year of life saved is well within the range for other commonly accepted medical interventions. Various studies have estimated that reduction in treatment costs through early screening detection may be 30% to 100% or more of the cost of screening. Magnetic resonance imaging (MRI) screening is also cost-effective for very high-risk women, such as BRCA carriers, and others at 20% or greater lifetime risk. Further studies are needed to determine whether MRI is cost-effective for those at moderately high (15%-20%) lifetime risk. Future technical advances could make MRI more cost-effective than it is today. Automated whole-breast ultrasonography will probably prove cost-effective as a supplement to mammography for women with dense breasts.

Multicenter surveillance of women at high genetic breast cancer risk using mammography, ultrasonography, and contrast-enhanced magnetic resonance imaging (the high breast cancer risk italian 1 study): final results

OBJECTIVES

: To prospectively compare clinical breast examination, mammography, ultrasonography, and contrast-enhanced magnetic resonance imaging (MRI) in a multicenter surveillance of high-risk women.

MATERIALS AND METHODS

: We enrolled asymptomatic women aged ≥ 25: BRCA mutation carriers; first-degree relatives of BRCA mutation carriers, and women with strong family history of breast/ovarian cancer, including those with previous personal breast cancer.

RESULTS

: A total of 18 centers enrolled 501 women and performed 1592 rounds (3.2 rounds/woman). Forty-nine screen-detected and 3 interval cancers were diagnosed: 44 invasive, 8 ductal carcinoma in situ; only 4 pT2 stage; 32 G3 grade. Of 39 patients explored for nodal status, 28 (72%) were negative. Incidence per year-woman resulted 3.3% overall, 2.1% <50, and 5.4% ≥ 50 years (P < 0.001), 4.3% in women with previous personal breast cancer and 2.5% in those without (P = 0.045). MRI was more sensitive (91%) than clinical breast examination (18%), mammography (50%), ultrasonography (52%), or mammography plus ultrasonography (63%) (P < 0.001). Specificity ranged 96% to 99%, positive predictive value 53% to 71%, positive likelihood ratio 24 to 52 (P not significant). MRI showed significantly better negative predictive value (99.6) and negative likelihood ratio (0.09) than those of the other modalities. At receiver operating characteristic analysis, the area under the curve of MRI (0.97) was significantly higher than that of mammography (0.83) or ultrasonography (0.82) and not significantly increased when MRI was combined with mammography and/or ultrasonography. Of 52 cancers, 16 (31%) were diagnosed only by MRI, 8 of 21 (38%) in women <50, and 8 of 31 (26%) in women ≥ 50 years of age.

CONCLUSION

: MRI largely outperformed mammography, ultrasonography, and their combination for screening high-risk women below and over 50.

Impact of MRI surveillance and breast cancer detection in young women with BRCA mutations

Based on several observational studies that have yielded consistent results, the combination of annual magnetic resonance imaging (MRI) plus mammography is now the standard of care for screening women with BRCA mutations who decline risk-reducing mastectomy. However, many of these women will develop breast cancer at a young age and, while most of these cancers will be very early stage, oncologists need to be aware of the unique issues faced by women in this age group due to the diagnosis and treatment. Fear of death, loss of fertility, premature menopause, relationship stress, career disruption and financial losses are only some of the problems that are either unique to young women or much more pronounced in this age group. Urgent referral to a fertility specialist of any woman who has not yet completed her family should be made as soon as the possible need for systemic treatment is recognized. The oncologist should also have a low threshold for referring young women to professionals experienced in navigating young women and their families through the psychosocial trauma of a breast cancer diagnosis.

Breast MRI in community practice: equipment and imaging techniques at facilities in the Breast Cancer Surveillance Consortium

PURPOSE

MRI is increasingly used for the detection of breast carcinoma. Little is known about breast MRI techniques among community practice facilities. The aim of this study was to evaluate equipment and acquisition techniques used by community facilities across the United States, including compliance with minimum standards by the ACRIN® 6667 Trial and the European Society of Breast Imaging.

METHODS

Breast Cancer Surveillance Consortium facilities performing breast MRI were identified and queried by survey regarding breast MRI equipment and technical parameters. Variables included scanner field strength, coil type, acquisition coverage, slice thickness, and the timing of the initial postcontrast sequence. Results were tallied and percentages of facilities meeting ACRIN® and European Society of Breast Imaging standards were calculated.

RESULTS

From 23 facilities performing breast MRI, results were obtained from 14 (61%) facilities with 16 MRI scanners reporting 18 imaging parameters. Compliance with equipment recommendations of ≥1.5-T field strength was 94% and of a dedicated breast coil was 100%. Eighty-three percent of acquisitions used bilateral postcontrast techniques, and 78% used slice thickness≤3 mm. The timing of initial postcontrast sequences ranged from 58 seconds to 8 minutes 30 seconds, with 63% meeting recommendations for completion within 4 minutes.

CONCLUSIONS

Nearly all surveyed facilities met ACRIN and European Society of Breast Imaging standards for breast MRI equipment. The majority met standards for acquisition parameters, although techniques varied, in particular for the timing of initial postcontrast imaging. Further guidelines by the ACR Breast MRI Accreditation Program will be of importance in facilitating standardized and high-quality breast MRI.

Probability of malignancy for lesions detected on breast MRI: a predictive model incorporating BI-RADS imaging features and patient characteristics

OBJECTIVES

To predict the probability of malignancy for MRI-detected breast lesions with a multivariate model incorporating patient and lesion characteristics.

METHODS

Retrospective review of 2565 breast MR examinations from 1/03-11/06. BI-RADS 3, 4 and 5 lesions initially detected on MRI for new cancer or high-risk screening were included and outcomes determined by imaging, biopsy or tumor registry linkage. Variables were indication for MRI, age, lesion size, BI-RADS lesion type and kinetics. Associations with malignancy were assessed using generalized estimating equations and lesion probabilities of malignancy were calculated.

RESULTS

855 lesions (155 malignant, 700 benign) were included. Strongest associations with malignancy were for kinetics (washout versus persistent; OR 4.2, 95% CI 2.5-7.1) and clinical indication (new cancer versus high-risk screening; OR 3.0, 95% CI 1.7-5.1). Also significant were age > = 50 years, size > = 10 mm and lesion-type mass. The most predictive model (AUC 0.70) incorporated indication, size and kinetics. The highest probability of malignancy (41.1%) was for lesions on MRI for new cancer, > = 10 mm with washout. The lowest (1.2%) was for lesions on high-risk screening, <10 mm with persistent kinetics.

CONCLUSIONS

A multivariate model shows promise as a decision support tool in predicting malignancy for MRI-detected breast lesions.

Background parenchymal enhancement on baseline screening breast MRI: impact on biopsy rate and short-interval follow-up

OBJECTIVE

Background parenchymal enhancement on breast MRI refers to normal enhancement of the patient's fibroglandular tissue. The aim of this study was to determine the effect of background parenchymal enhancement on short-interval follow-up, biopsy, and cancer detection rate on baseline screening MRI in a high-risk group.

MATERIALS AND METHODS

Two hundred fifty baseline high-risk screening MRI examinations were reviewed. For each, the background parenchymal enhancement pattern was recorded (minimal, ≤ 25%; mild, 26-50%; moderate, 51-75%; and marked, > 75%), as were BI-RADS category, biopsy rate, and final pathology result. Results were compared for each enhancement category.

RESULTS

Of the 250 MRI examinations, 24.8% showed minimal enhancement; 34%, mild; 24%, moderate; and 17.2%, marked enhancement. Women with minimal enhancement had a significantly higher number of BI-RADS categories 1 and 2 examinations (64.5%) than women with mild (38.8%), moderate (40%), or marked (25.6%) enhancement. The BI-RADS category 3 rate was 43.6% overall and was significantly lower for women with minimal enhancement (27.4% vs 47.1% for women with mild, 45.0% for women with moderate, and 58.1% for women with marked enhancement). At follow-up, 86.2% of the BI-RADS 3 lesions were converted to BI-RADS category 1 or 2 and 13.8% were converted to BI-RADS 4, with a malignancy rate of 0.9% for lesions undergoing short-interval follow-up. There was no significant difference in biopsy rate or cancer detection rate among enhancement categories.

CONCLUSION

Mild, moderate, and marked background parenchymal enhancement is associated with a significantly lower rate of BI-RADS categories 1 and 2 assessments and a significantly higher rate of BI-RADS category 3 assessments than minimal enhancement. There was no significant difference in biopsy rate or cancer detection rate among the enhancement categories.

Evaluation of clinical breast MR imaging performed with prototype computer-aided diagnosis breast MR imaging workstation: reader study

PURPOSE

To evaluate a computer-aided diagnosis (CADx) system for dynamic contrast material-enhanced magnetic resonance (MR) imaging and compare it with a currently used clinical method of interpreting breast MR image findings that includes the use of commercially available automated software for kinetic image data processing and visualization.

MATERIALS AND METHODS

In this HIPAA-compliant, institutional review board-approved study, a training set of 121 breast lesions (77 malignant, 44 benign) was used to train the CADx system. After practicing with 10 training cases, six breast imaging radiologists assessed the likelihood of malignancy and the need for biopsy with a separate test set of 60 lesions (30 malignant, 30 benign). Their performances in differentiating between benign and malignant breast lesions both without (conventional lesion viewing, output from commercially available breast MR imaging analysis software) and with the aid of the CADx workstation (with classification yielding an estimation of the probability of malignancy for each lesion) were evaluated with receiver operating characteristic analysis.

RESULTS

When CADx was used, the average performance of the radiologists was significantly improved, as indicated by increases in mean area under the receiver operating characteristic curve (from 0.80 to 0.84, P = .007), mean sensitivity (from 83% to 88%, P = .001), and average number of biopsy recommendations for malignant cases (1.7 more biopsies for malignant lesions with use of CADx, P = .032). Although the mean specificity improved (from 50% to 53%), the improvement was not significant (P = .2).

CONCLUSION

Use of the CADx system improved the radiologists' performance in differentiating between malignant and benign MR imaging-depicted breast lesions.

Multilevel analysis of spatiotemporal association features for differentiation of tumor enhancement patterns in breast DCE-MRI

PURPOSE

Analyzing spatiotemporal enhancement patterns is an important task for the differential diagnosis of breast tumors in dynamic contrast-enhanced MRI (DCE-MRI), and yet remains challenging because of complexities in analyzing the time-series of three-dimensional image data. The authors propose a novel approach to breast MRI computer-aided diagnosis (CAD) using a multilevel analysis of spatiotemporal association features for tumor enhancement patterns in DCE-MRI.

METHODS

A database of 171 cases consisting of 111 malignant and 60 benign tumors was used. Time-series contrast-enhanced MR images were obtained from two different types of MR scanners and protocols. The images were first registered for motion compensation, and then tumor regions were segmented using a fuzzy c-means clustering-based method. Spatiotemporal associations of tumor enhancement patterns were analyzed at three levels: Mapping of pixelwise kinetic features within a tumor, extraction of spatial association features from kinetic feature maps, and extraction of kinetic association features at the spatial feature level. A total of 84 initial features were extracted. Predictable values of these features were evaluated with an area under the ROC curve, and were compared between the spatiotemporal association features and a subset of simple form features which do not reflect spatiotemporal association. Several optimized feature sets were identified among the spatiotemporal association feature group or among the simple feature group based on a feature ranking criterion using a support vector machine based recursive feature elimination algorithm. A least-squares support vector machine (LS-SVM) classifier was used for tumor differentiation and the performances were evaluated using a leave-one-out testing.

RESULTS

Predictable values of the extracted single features ranged in 0.52-0.75. By applying multilevel analysis strategy, the spatiotemporal association features became more informative in predicting tumor malignancy, which was shown by a statistical testing in ten spatiotemporal association features. By using a LS-SVM classifier with the optimized second and third level feature set, the CAD scheme showed Az of 0.88 in classification of malignant and benign tumors. When this performance was compared to the same LS-SVM classifier with simple form features which do not reflect spatiotemporal association, there was a statistically significant difference (0.88 vs 0.79, p <0.05), suggesting that the multilevel analysis strategy yields a significant performance improvement.

CONCLUSIONS

The results suggest that the multilevel analysis strategy characterizes the complex tumor enhancement patterns effectively with the spatiotemporal association features, which in turn leads to an improved tumor differentiation. The proposed CAD scheme has a potential for improving diagnostic performance in breast DCE-MRI.

[New information on high risk breast screening]

Women with an elevated risk for breast cancer require intensified screening beginning at an early age. Such high risk screening differs considerably from screening in the general population. After an expert has evaluated the exact risk a breast MRI examination should be offered at least once a year and beginning latest at the age of 30 depending on the patients risk category. Complementary mammograms should not be performed before the age of 35. An additional ultrasound examination is no longer recommended. To ensure a high sensitivity and specificity high risk screening should be performed only at a nationally or regionally approved and audited service. Adequate knowledge about the phenotypical characteristics of familial breast cancer is essential. Besides the common malignant phenotypes, benign morphologies (round or oval shape and smooth margins) as well as a low prevalence of calcifications have been described. Using MRI benign contrast media kinetics as well as non-solid lesions with focal, regional and segmental enhancement can often be visualized.

Comparative effectiveness of screening and prevention strategies among BRCA1/2-affected mutation carriers

Comparative effectiveness research has become an integral part of health care planning in most developed countries. In a simulated cohort of women, aged 30-65, who tested positive for BRCA1 or BRCA2 mutations, we compared outcomes of mammography with and without MRI, prophylactic oophorectomy with and without mastectomy, mastectomy alone, and chemoprevention.

METHODS

Using Treeage 9.02 software, we developed Markov models with 25,000 Monte Carlo simulations and conducted probabilistic sensitivity analysis. We based mutation penetrance rates, breast and ovarian cancer incidence, and mortality rates, and costs in terms of 2009 dollars, on published studies and data from the Surveillance, Epidemiology, and End RESULTS (SEER) Program and the Centers for Medicare and Medicaid Services. We used preference ratings obtained from mutation carriers and controls to adjust survival for quality of life (QALYs).

RESULTS

For BRCA1 mutation carriers, prophylactic oophorectomy at $1,741 per QALY, was more cost effective than both surgeries and dominated all other interventions. For BRCA2 carriers, prophylactic oophorectomy, at $4,587 per QALY, was more cost effective than both surgeries. Without quality adjustment, both mastectomy and BSO surgeries dominated all other interventions. In all simulations, preventive surgeries or chemoprevention dominated or were more cost effective than screening because screening modalities were costly.

CONCLUSION

Our analysis suggested that among BRCA1/2 mutation carriers, prophylactic surgery would dominate or be cost effective compared to chemoprevention and screening. Annual screening with MRI and mammography was the most effective strategy because it was associated with the longest quality-adjusted survival, but it was also very expensive.

PET in women with high risk for breast or ovarian cancer

Data on the use of PET in women with genetic or familial high-risk for breast or ovarian cancer are scarce. Open issues include the complementary use of dedicated breast-PET scanners in patients at high-risk for breast cancer, the relation between pathological characteristics of cancer diagnosed in BRCA carriers and (18)F-fluorodeoxyglucose ((18)F-FDG)-avidity, and the predictive value of PET in patients at high-risk for ovarian cancer presenting with a pelvic mass or potential chemical markers. Therefore, the use of PET in high-risk patients with unproven malignant disease needs to be investigated in well designed clinical trials. Once breast or ovarian cancer is diagnosed, indications for (18)F-FDG-PET or PET-CT imaging are similar for high-risk patients and patients with sporadic cancer. However, PET can provide data that are beyond tumour detection per se. Future directions of PET in high-risk patients might include monitoring the response of BRCA carriers to new treatments such as poly-ADP ribose polymerase (PARP) inhibitors, personalisation of treatment, and the use of new PET tracers to investigate the tissue changes related to increased risk for breast and ovarian cancer.

The utility of breast MRI in the management of breast cancer

Breast magnetic resonance imaging (MRI) is increasingly used in the evaluation of breast cancer. The impact of this modality on patient management at a single institution is evaluated in this paper. A retrospective review was performed for 114 breast cancer patients who had breast MRI as part of their diagnostic evaluation. Clinical information, mammograms, breast ultrasounds and MRI scans were reviewed to determine whether the MRI findings led to a change in patient management. Outcomes as the result of breast MRI were stratified as favorable and unfavorable. Ninety-five patients who had complete clinical, radiologic, and pathologic data were identified. The indications for breast MRI included: high risk screening (n = 3), diagnostic evaluation of disease after neo-adjuvant chemotherapy (n = 24) or prior to re-excision (n = 8), extent of in situ ductal, infiltrating ductal or infiltrating lobular disease histology (DCIS n = 3, IDC n = 24, ILC n = 17), identification of unknown primary (n = 2), assessment of contralateral breast (n = 4), recurrence surveillance (n = 5), and other (n = 5). MRI was concordant with clinical findings and other modalities in 70.5% of cases. MRI altered planned clinical management in 28 of 95 patients (29.5%). Management changes were favorable in 21 patients (75%). Diagnostic evaluation of the breast by MRI alters patient management in 30% of cases depending upon the indications. Alteration in patient management is favorable in 75% of cases. Evaluation of the breast by MRI alters the clinical management of nearly one-third of patients. Changes are favorable for the majority of these cases. Patients undergoing evaluation for contralateral disease, invasive lobular carcinoma and assessment of chemotherapeutic response may derive a more meaningful benefit from MRI.

Breast cancer screening with imaging: recommendations from the Society of Breast Imaging and the ACR on the use of mammography, breast MRI, breast ultrasound, and other technologies for the detection of clinically occult breast cancer

Screening for breast cancer with mammography has been shown to decrease mortality from breast cancer, and mammography is the mainstay of screening for clinically occult disease. Mammography, however, has well-recognized limitations, and recently, other imaging including ultrasound and magnetic resonance imaging have been used as adjunctive screening tools, mainly for women who may be at increased risk for the development of breast cancer. The Society of Breast Imaging and the Breast Imaging Commission of the ACR are issuing these recommendations to provide guidance to patients and clinicians on the use of imaging to screen for breast cancer. Wherever possible, the recommendations are based on available evidence. Where evidence is lacking, the recommendations are based on consensus opinions of the fellows and executive committee of the Society of Breast Imaging and the members of the Breast Imaging Commission of the ACR.

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.

Prospective multicenter cohort study to refine management recommendations for women at elevated familial risk of breast cancer: the EVA trial

PURPOSE

We investigated the respective contribution (in terms of cancer yield and stage at diagnosis) of clinical breast examination (CBE), mammography, ultrasound, and quality-assured breast magnetic resonance imaging (MRI), used alone or in different combination, for screening women at elevated risk for breast cancer.

METHODS

Prospective multicenter observational cohort study. Six hundred eighty-seven asymptomatic women at elevated familial risk (> or = 20% lifetime) underwent 1,679 annual screening rounds consisting of CBE, mammography, ultrasound, and MRI, read independently and in different combinations. In a subgroup of 371 women, additional half-yearly ultrasound and CBE was performed more than 869 screening rounds. Mean and median follow-up was 29.18 and 29.09 months.

RESULTS

Twenty-seven women were diagnosed with breast cancer: 11 ductal carcinoma in situ (41%) and 16 invasive cancers (59%). Three (11%) of 27 were node positive. All cancers were detected during annual screening; no interval cancer occurred; no cancer was identified during half-yearly ultrasound. The cancer yield of ultrasound (6.0 of 1,000) and mammography (5.4 of 1,000) was equivalent; it increased nonsignificantly (7.7 of 1,000) if both methods were combined. Cancer yield achieved by MRI alone (14.9 of 1,000) was significantly higher; it was not significantly improved by adding mammography (MRI plus mammography: 16.0 of 1,000) and did not change by adding ultrasound (MRI plus ultrasound: 14.9 of 1,000). Positive predictive value was 39% for mammography, 36% for ultrasound, and 48% for MRI.

CONCLUSION

In women at elevated familial risk, quality-assured MRI screening shifts the distribution of screen-detected breast cancers toward the preinvasive stage. In women undergoing quality-assured MRI annually, neither mammography, nor annual or half-yearly ultrasound or CBE will add to the cancer yield achieved by MRI alone.

Reasons women at elevated risk of breast cancer refuse breast MR imaging screening: ACRIN 6666

PURPOSE

To determine reasons for nonparticipation in a trial of supplemental screening with magnetic resonance (MR) imaging after mammography and ultrasonography (US).

MATERIALS AND METHODS

Women(n = 2809) at elevated risk of breast cancer were enrolled in the American College of Radiology Imaging Network 6666 US Screening Protocol at 21 institutions. Fourteen institutions met technical and experience requirements for this institutional review board-approved, HIPAA-compliant substudy of supplemental screening with MR imaging. Those women who had completed 0-, 12-, and 24-month screenings with mammography combined with US were considered for a single contrast material-enhanced MR examination within 8 weeks after completing the 24-month mammography-US screening. A total of 1593 women had complete MR substudy registration data: 378 of them were ineligible for the study, and 1215 had analyzable data. Reasons for nonparticipation were determined. Demographic data were compared between study participants and nonparticipants.

RESULTS

Of 1215 women with analyzable data, 703 (57.9%), with a mean age of 54.8 years, were enrolled in the MR substudy and 512 (42.1%) declined participation. Women with a 25% or greater lifetime risk of breast cancer were more likely to participate (odds ratio, 1.53; 95% confidence interval: 1.10, 2.12). Of 512 nonparticipants, 130 (25.4%) refused owing to claustrophobia; 93 (18.2%), owing to time constraints; 62 (12.1%), owing to financial concerns; 47 (9.2%), because their physician would not provide a referral and/or did not believe MR imaging was indicated; 40 (7.8%), because they were not interested; 39 (7.6%), because they were medically intolerant to MR imaging; 29 (5.7%), because they did not want to undergo intravenous injection; 27 (5.3%), owing to additional biopsy or other procedures that might be required subsequently; 21 (4.1%), owing to MR imaging scheduling constraints; 11 (2.2%), because of the travel required; seven (1.4%), owing to gadolinium-related risks or allergies; and six (1.2%), for unknown reasons.

CONCLUSION

Of 1215 women with elevated breast cancer risk who could, according to protocol guidelines, undergo breast MR imaging, only 57.9% agreed to participate.

Relating dose of contrast media administered to uptake and washout of malignant lesions on DCEMRI of the breast

RATIONALE AND OBJECTIVES

To quantify the relationship between dose of contrast administered and contrast kinetics of malignant breast lesions.

MATERIALS AND METHODS

A total of 108 patients with 120 malignant lesions were selected for an institutional review board-approved review. Dynamic magnetic resonance protocol: one pre- and three or five post-contrast (at a fixed volume of 20 mL of 0.5 M gadodiamide) images. Patients were stratified into groups based on dose of contrast administered, after calculation of body weight (kg): Dose Group 1, <0.122 mmol/kg; Dose Group 2, 0.123-0.155 mmol/kg; Dose Group, 3 > 0.155 mmol/kg. Analysis of kinetic curve shape was made according to the Breast Imaging Reporting and Data System lexicon. Several quantitative parameters were calculated including initial and peak enhancement percentage (E(1) and E(peak)). Linear regression was used to model the variation of kinetic parameters with dose.

RESULTS

There was no difference found in the qualitative Breast Imaging Reporting and Data System descriptors of curve shape between the three dose groups. There was a trend for E(1) and E(peak) to increase from Dose Group 1 to Dose Group 3 in malignant lesions overall, as well as in invasive ductal carcinoma lesions separately. Each decrement/increment of 0.05 mmol/kg in dose yielded a decrease/increase of 78% and 97% in E(1) for in situ and invasive cancers, respectively.

CONCLUSION

Contrast should be administered at fixed dose to achieve comparable levels of lesion uptake in women of different weights. Our results suggest that reducing the contrast administered to 0.05 mmol/kg, as has been suggested for patients at risk of developing nephrogenic systemic fibrosis, could substantially decrease the observed initial enhancement in some cancers.