Evaluation of pectoralis major muscle in patients with posterior breast tumors on breast MR images: early experience

Preoperative Breast Magnetic Resonance Imaging: An Ontario Health (Cancer Care Ontario) Clinical Practice Guideline

BACKGROUND

The use of preoperative breast magnetic resonance imaging (MRI) after the diagnosis of breast cancer by mammography and/or ultrasound is inconsistent.

METHODS

After conducting a systematic review and meta-analysis comparing preoperative breast MRI versus no MRI, we reconvened to prepare a clinical practice guideline on this topic.

RESULTS

Based on the evidence that MRI improved recurrence, decreased the rates of reoperations (re-excisions or conversion mastectomy), and increased detection of synchronous contralateral breast cancer, we recommend that preoperative breast MRI should be considered on a case-by-case basis in patients diagnosed with breast cancer for whom additional information about disease extent could influence treatment. Based on stronger evidence, preoperative breast MRI is recommended in patients diagnosed with invasive lobular carcinoma for whom additional information about disease extent could influence treatment. For both recommendations, the decision to proceed with MRI would be conditional on shared decision-making between care providers and the patient, taking into account the benefits and risks of MRI as well as patient preferences. Based on the opinion of the Working Group, preoperative breast MRI is also recommended in the following more specific situations: (a) to aid in surgical planning of breast conserving surgery in patients with suspected or known multicentric or multifocal disease; (b) to identify additional lesions in patients with dense breasts; (c) to determine the presence of pectoralis major muscle/chest wall invasion in patients with posteriorly located tumours or when invasion of the pectoralis major muscle or chest wall is suspected; (d) to aid in surgical planning for skin/nipple-sparing mastectomies, autologous reconstruction, oncoplastic surgery, and breast conserving surgery with suspected nipple/areolar involvement; and (e) in patients with familial/hereditary breast cancer but who have not had recent breast MRI as part of screening or diagnosis.

Invasive Lobular Carcinoma: A Review of Imaging Modalities with Special Focus on Pathology Concordance

Invasive lobular cancer (ILC) is the second most common type of breast cancer. It is characterized by a unique growth pattern making it difficult to detect on conventional breast imaging. ILC can be multicentric, multifocal, and bilateral, with a high likelihood of incomplete excision after breast-conserving surgery. We reviewed the conventional as well as newly emerging imaging modalities for detecting and determining the extent of ILC- and compared the main advantages of MRI vs. contrast-enhanced mammogram (CEM). Our review of the literature finds that MRI and CEM clearly surpass conventional breast imaging in terms of sensitivity, specificity, ipsilateral and contralateral cancer detection, concordance, and estimation of tumor size for ILC. Both MRI and CEM have each been shown to enhance surgical outcomes in patients with newly diagnosed ILC that had one of these imaging modalities added to their preoperative workup.

Breast Cancer Staging: Updates in the AJCC Cancer Staging Manual, 8th Edition, and Current Challenges for Radiologists, From the AJR Special Series on Cancer Staging

The standardization of the AJCC TNM staging system for breast cancer allows physicians to evaluate patients with breast cancer using standard language and criteria, assess treatment response, and compare patient outcomes. Previous editions of the AJCC Cancer Staging Manual relied on the anatomic TNM method of staging that incorporates imaging and uses population-level survival data to predict patient outcomes. Recent advances in therapy based on biomarker status and multigene panels have improved treatment strategies. In the newest edition of the AJCC Cancer Staging Manual (8th edition, adopted on January 1, 2018), breast cancer staging integrates anatomic staging with tumor grade, biomarker data regarding hormone receptor status, oncogene expression, and gene expression profiling to assign a prognostic stage. This article reviews the 8th edition of the AJCC breast cancer staging system with a focus on anatomic staging and the challenges that anatomic staging poses for radiologists. We highlight key imaging findings that impact patient treatment and discuss the role of imaging in evaluating response to neoadjuvant therapy. Finally, we discuss biomarkers and multigene panels and how these impact prognostic stage. The review will help radiologists identify critical findings that affect breast cancer staging and understand ongoing limitations of imaging in staging.

Breast cancer abutting the pectoralis major muscle on breast MRI: what are the clinical implications?

OBJECTIVES

Defining the posterior extent of breast cancer prior to surgery has clinical implications. However, there are limited data available to guide the interpretation of breast cancers seen on MRI that abut the pectoralis muscle but lack associated muscle enhancement.

METHODS

In this retrospective study of breast MRIs performed between May 2008 and July 2019, 43 female patients demonstrated breast cancers abutting the pectoralis muscle without enhancement of the muscle itself. Imaging features of the cancers as well as pathologic and clinical outcomes were recorded. Statistical analyses of associations between imaging findings and clinical outcomes were performed using Fisher's exact test, logistic regression, a Mann-Whitney U test and/or Student's t-test.

RESULTS

The pectoralis major muscle was pathologically invaded by carcinoma in 4/43 (9.3%). There was no significant association between pectoralis muscle invasion and any MR imaging feature of the breast cancer. Tumors causing deformation of the muscle contour by MRI, tumors larger in size, tumors with a larger extent abutting the muscle and tumors in which the imaging feature abutting the muscle was a mass or non-mass enhancement (rather than a spicule) were more commonly seen in patients with muscle invasion, although these did not reach statistical significance (p > 0.05).

CONCLUSION

In this study, a lack of pectoralis muscle enhancement by MRI did not exclude pathologic muscle invasion by breast cancers abutting the muscle.

ADVANCES IN KNOWLEDGE

Knowledge of the likelihood of pectoralis muscle involvement for breast cancers abutting the pectoralis muscle on MRI may guide accurate interpretation and definition of the posterior extent of disease.

The Radiologist's Role in a Breast Multidisciplinary Tumor Board

Breast multidisciplinary tumor boards (MTBs) play an important role in determining treatment. This article serves as a guide for the radiologist participating in a breast MTB, as the information presented at MTB can significantly influence treatment plans and dictate future steps for further patient work-up. Multidisciplinary tumor board preparation involves a careful review of the patient's history while gathering all relevant imaging studies, and reinterpreting them when appropriate. Presented images should be carefully selected, annotated, and displayed clearly before providing final recommendations for localization and incompletely assessed findings. Anatomic staging factors from the AJCC Breast Cancer Staging System, such as tumor size and degree of suspected skin involvement, should be described. In addition, there are many other types of information that the treatment specialists want to know. The surgeon is interested in anatomic information that will help them decide whether breast conservation therapy is feasible or if local structures, such as the nipple, can be spared. The radiation oncologist may need to know whether accelerated partial breast irradiation is feasible or if postmastectomy radiation therapy is indicated. The medical oncologist is looking for factors that may provide an indication for neoadjuvant therapy and ensuring there is a reliable follow-up method for evaluating the response to treatment, such as comparative MRI. Additionally, all specialists need to know the extent of suspected nodal involvement. By clearly and comprehensively presenting this information to the rest of the MTB team, the radiologist provides a vital contribution that guides treatment and ensures adherence to clinical guidelines.

A Clinical Approach to Diffusion-Weighted Magnetic Resonance Imaging in Evaluating Chest Wall Invasion of Breast Tumors

Objective:

The purpose of this study is to evaluate diffusion weighted magnetic rsonance imaging (MRI) acquisitions in delineating posterior extent of breast tumors and in predicting chest wall invasion prior to treatment. To our knowledge, there has not been any literature specifically evaluating the utility of diffusion-weighted acquisitions in chest wall invasion of breast tumors.

Materials and Methods:

A retrospective review of our breast imaging database for keywords “chest wall invasion” and “breast MRI” was performed over the last 14 years. Diffusion sequences, T1 sequences (pre and post contrast), and T2 sequences were evaluated. Apparent diffusion coefficient (ADC) values in tumor and chest wall were assessed. Imaging findings were correlated with surgical pathology.

Results:

23 patients met inclusion criteria. All 23 had loss of fat plane on T2 sequences. 22/23 had loss of fat plane on postcontrast T1 sequences. Pectoralis muscle enhancement was present in 19/23 (83%) tumors and chest wall enhancement was present 9/23 (39%) tumors. Qualitative restricted diffusion within the pectoralis muscle was present in 18/23 (71%) tumors and in the chest wall was present in 8/23 (35%) tumors. Mean ADC values were 1.15 s/mm² in the tumor and 1.29 s/mm² in the chest wall. Sensitivity, specificity, positive predictive value and negative predictive value were 100%, 36%, 63%, and 100% for chest wall enhancement respectively and 69%, 36%, 61%, and 80% for chest wall diffusion-weighted imaging restriction respectively.

Conclusion:

Diffusion weighted sequences can be helpful in characterizing chest wall invasion of breast tumors.

Introduction of a New Staging System of Breast Cancer for Radiologists: An Emphasis on the Prognostic Stage

In 2017, the American Joint Committee on Cancer announced the 8th edition of its cancer staging system. For breast cancer, the most significant change in the staging system is the incorporation of biomarkers into the anatomic staging to create prognostic stages. Different prognostic stages are assigned to tumors with the same anatomic stages according to the tumor grade, hormone receptor (estrogen receptor; progesterone receptor) status, and HER2 status. A Clinical Prognostic Stage is assigned to all patients regardless of the type of therapy used; in contrast, a Pathologic Prognosis Stage is assigned to patients in whom surgery is the initial treatment. In a few situations, low Oncotype DX recurrence scores can change the prognostic stage. The radiologists need to understand the importance of the biologic factors that can influence cancer staging.

Preoperative imaging for breast conservation surgery-do we need more than conventional imaging for local disease assessment?

Breast conservation surgery (BCS) is offered for early breast cancer. Conventional imaging with mammography and ultrasound would have been performed prior to surgery. This article considers other imaging modalities available [such as 3D tomosynthesis, magnetic resonance imaging (MRI), contrast-enhanced spectral mammography, positron emission mammography (PEM), breast-specific gamma imaging (BSGI) and cone beam computed tomography (CBCT)] and discusses the evidence for these in terms of diagnostic accuracy and clinical outcomes.

MRI for the Staging and Evaluation of Response to Therapy in Breast Cancer

Breast magnetic resonance imaging (MRI) is the most sensitive of the available imaging modalities to characterize breast cancer. Breast MRI has gained clinical acceptance for screening high-risk patients, but its role in the preoperative imaging of breast cancer patients remains controversial. This review focuses on the current indications for staging breast MRI, the evidence for and against the role of breast MRI in the preoperative staging workup, and the evaluation of treatment response of breast cancer patients.

Clinical Breast Magnetic Resonance Imaging: Technique, Indications, and Future Applications

Breast magnetic resonance imaging (MRI) is the most sensitive imaging modality for the detection of breast cancer, and it is indicated for breast cancer screening in patients at high-risk of developing breast cancer. It is limited to this group given the high cost. In addition, breast MRI is also indicated for evaluating the extent of disease in patients with new breast cancer diagnoses, monitoring the response to neoadjuvant treatment, and evaluating implant integrity. New promising innovations in breast MRI include fast abbreviated MRI, and functional techniques including diffusion-weighted imaging and magnetic resonance spectroscopy are promising particularly as regards to treatment response.

Wide-field tissue polarimetry allows efficient localized mass spectrometry imaging of biological tissues

While mass spectrometers can detect chemical signatures within milliseconds of data acquisition time, the non-targeted nature of mass spectrometry imaging (MSI) necessitates probing the entire surface of the sample to reveal molecular composition even if the information is only sought from a sample subsection. This leads to long analysis times. Here, we used polarimetry to identify, within a biological tissue, areas of polarimetric heterogeneity indicative of cancer. We were then able to target our MS analysis using polarimetry results to either the cancer region itself or to the cancer margin. A tandem of polarimetry and Desorption Electrospray Ionization Mass Spectrometry Imaging (DESI-MSI) enables fast (10 fold compared to non-targeted imaging), and accurate pathology assessment (cancer typification in less than 2 minutes compared to 30 minutes for histopathology) of ex vivo tissue slices, without additional sample preparation. This workflow reduces the overall analysis time of MSI as a research tool.

Breast magnetic resonance imaging performance: safety, techniques, and updates on diffusion-weighted imaging and magnetic resonance spectroscopy

Dynamic contrast-enhanced breast magnetic resonance imaging (MRI) is a well-established, highly sensitive technique for the detection and evaluation of breast cancer. Optimal performance of breast MRI continues to evolve. This article addresses breast MRI applications, covers emerging breast MRI safety concerns; outlines the technical aspects of breast MRI, including equipment and protocols at 3 T and 1.5 T; and describes current promising areas of research including diffusion-weighted imaging and magnetic resonance spectroscopy.

Location of triple-negative breast cancers: comparison with estrogen receptor-positive breast cancers on MR imaging

There has been a major need to better understand the biological characteristics of triple-negative breast cancers. Compared with estrogen receptor (ER)-positive cancers, several magnetic resonance (MR) imaging findings have been reported as characteristic findings. However, information regarding their location has not been described. Our study was to compare the location of triple-negative breast cancers with that of ER-positive breast cancers using magnetic resonance (MR) imaging. The locations of 1102 primary breast cancers (256 triple-negative and 846 ER-positive) in 1090 women (mean, 52.1 years) were reviewed using three-dimensional (3D) coordinates. The x-axis measurement was recorded as the transverse distance from the posterior nipple line; y-axis measurement as the anteroposterior distance from the chest wall; z-axis measurement as the superoinferior distance from the posterior nipple line. The association between breast cancer subtype and tumor location was evaluated using multiple linear regression analysis. Triple-negative breast cancers were significantly closer to the chest wall than ER-positive breast cancers in absolute (1.8 cm vs. 2.3 cm, P < .0001) and normalized (0.21 vs. 0.25, P < .0001) y-axis distances. The x- and z-axes distances were not significantly different between triple-negative and ER-positive breast cancers. Multiple linear regression analysis revealed that age, mammographic density, axillary nodal status, and triple-negative subtype were significantly associated with absolute and normalized distances from the chest wall (all P < .05). Our results show that triple-negative breast cancers have a tendency toward a posterior or prepectoral location compared with ER-positive breast cancers.

Radiologist's role in breast cancer staging: providing key information for clinicians

Breast cancer is the second leading cause of cancer death in women, exceeded only by lung cancer, and the 5-year survival rate is largely dependent on disease stage. The American Joint Committee on Cancer (AJCC) staging system for breast cancer (7th edition) provides a tumor-node-metastasis (TNM) classification scheme for breast cancer that is important for determining prognosis and treatment. Ascertaining the correct stage of breast cancer can be challenging, and the importance of the radiologist's role has increased over the years. The radiologist should understand how breast cancer stage is assigned and should be familiar with the AJCC's TNM classification scheme. The authors review the AJCC's TNM staging system for breast cancer with emphasis on clinical and preoperative staging, the different imaging modalities used in staging, and the key information that should be conveyed to clinicians. Radiologic information that may alter stage, prognosis, or treatment includes tumor size; number of tumor lesions; total span of disease; regional nodal status (axillary levels I-III, internal mammary, supraclavicular); locoregional invasion (involvement of the pectoralis muscle, skin, nipple, or chest wall); and distant metastases to bone, lung, brain, and liver, among other anatomic structures.

Breast magnetic resonance imaging indications in current practice

Although mammography is the primary imaging modality for the breast, it has its limitations especially with dense breast parenchyma. Breast magnetic resonance imaging (MRI) has evolved into an important adjunctive tool as it is currently the most sensitive technique for breast cancer detection. Despite this high sensitivity, overlap in the appearances of some benign and malignant breast lesions results in additional unnecessary intervention with negative results. These false positives, in addition to high cost and limited availability, necessitate establishing proper indications for breast MRI. The literature was here reviewed for recent clinical trials, meta-analyses and review papers which have studied this important subject. PubMed; the US national library of medicine, was utilized to review the literature in the last twenty years. Using the obtained information, current uses of breast MRI are discussed in this paper to determine the indications which are relevant to clinical practice.

Magnetic resonance imaging features in triple-negative breast cancer: comparison with luminal and HER2-overexpressing tumors

BACKGROUND

It has been ascertained that triple-negative (TN) breast cancer is characterized by an aggressive clinical course and a poor prognosis. The purpose of our study was to compare the magnetic resonance imaging (MRI) features of the 3 major different breast cancer subtypes (TN, luminal, and human epidermal growth factor receptor 2 [HER2]-overexpressing) and to suggest the criteria that might predict TN phenotype.

MATERIALS AND METHODS

From October 2007 to April 2011, we studied 77 patients with histologically confirmed TN breast cancer who underwent breast MRI. We randomly included 148 patients with non-TN breast cancer (110 luminal and 38 HER-overexpressing) as a control group. We evaluated the clinicopathologic data, the MRI morphologic and kinetic features, the signal intensity on T2-weighted images, and the apparent diffusion coefficient (ADC).

RESULTS

Our results confirmed that TN tumors are more aggressive, are usually diagnosed at a younger age compared with the other study groups, and show benign morphologic features with MRI. Backward stepwise logistic regression identified some parameters as independent predictors of TN-type lesions: age, size, shape, presence of edema, and infiltrative characteristics. The receiver operating characteristic (ROC) curve, built with 4 of 5 these factors as criteria to predict TN status, showed a 0.664 area under the curve (AUC) value (sensitivity 58.4%, specificity 73.2%). The inclusion of the fifth criterion showed a 0.699 AUC value (sensitivity, 49.4%; specificity, 89.4%).

CONCLUSION

We identified the clinicoradiologic parameters that are independent predictors of TN breast lesions, which might be helpful for earlier prediction of the TN status of a breast lesion.

Advances in oncologic imaging: update on 5 common cancers

Imaging has become a pivotal component throughout a patient's encounter with cancer, from initial disease detection and characterization through treatment response assessment and posttreatment follow-up. Recent progress in imaging technology has presented new opportunities for improving clinical care. This article provides updates on the latest approaches to imaging of 5 common cancers: breast, lung, prostate, and colorectal cancers, and lymphoma.

Diagnostic magnetic resonance imaging of the breast

Contrast enhanced breast magnetic resonance imaging is a modality that is frequently used into the breast radiologist's daily clinical practice. MRI examination should have optimal technical proficiency in order to attain diagnostic quality avoiding false positive and negative diagnoses. Furthermore, due to increasing usage fields of the examinations uniting with high sensitivity phenomenon, excessive usage and excision/interventional procedures are inevitable. Therefore, we hope to highlight the appropriate usage of the MRI technique and it's clinical applications.

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.

MRI for breast cancer: Current indications

Mammography is the only imaging study that has been proven in multiple large randomized trials to decrease breast cancer mortality. Mammography, however, has its limitations and, as such, other modalities that can complement it are being studied. One of these is dynamic contrast-enhanced breast MRI, which has emerged as an important adjunctive modality and is at present the most sensitive modality that we have to evaluate the breast. The American College of Radiology, in its 2004 practice guidelines, has outlined the 12 current indications for breast MRI. This manuscript reviews and provides examples of each of these.

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.

Indications for breast MRI: self-assessment module

The educational objectives for this self-assessment module are for the participant to exercise, self-assess, and improve his or her understanding of breast MRI.

Breast MR imaging: current indications and advanced imaging techniques

Breast cancer is the most common solid tumor diagnosed in women. In the past decades, great strides have been made in breast cancer screening. While multiple screening trials have shown the benefits of screening mammography, there are limitations to x-ray mammography. Given these inherent limitations, efforts have been made to develop adjunctive imaging techniques, including screening ultrasonography, gamma-specific breast imaging, breast tomosynthesis, dedicated breast computed tomography, and breast magnetic resonance (MR) imaging. This article addresses the current indications and advanced imaging applications of breast MR imaging.

Diagnostic breast MR imaging: current status and future directions

Breast MRI has become an integral component in breast imaging. Indications have become clearer and better defined. Guidelines and recommendations are evolving and many are recognized and published. Future applications are exciting and may possibly improve our ability to diagnose breast cancer, improving the patient's treatment options and ultimately patient outcome.

Evolving Role of MRI in Breast Cancer Imaging

Breast MRI is a useful adjunctive tool to mammography. In the past 2 decades, contrast-enhanced breast MRI has become an integral component of breast imaging. In patients with known breast cancer, breast MRI can assess the extent of disease, including multifocal tumors and chest wall invasion. Improvements in MRI technology have resulted in improved ability for diagnosing mammographically and clinically occult breast cancer. With the use of contrast, the sensitivity of breast MRI for assessing invasive breast cancer approaches 100%, although specificity is lower. The clinical indications for the use of breast MRI will continue to evolve and expand.

Significance of breast lesion descriptors in the ACR BI-RADS MRI lexicon

In recent years, dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has altered the clinical management for women with breast cancer. In March 2007, the American Cancer Society (ACS) issued a new guideline recommending annual MRI screening for high-risk women. This guideline is expected to substantially increase the number of women each year who receive breast MRI. The diagnosis of breast MRI involves the description of morphological and enhancement kinetics features. To standardize the communication language, the Breast Imaging Reporting and Data System (BI-RADS) MRI lexicon was developed by the American College of Radiology (ACR). In this article, the authors will review various appearances of breast lesions on MRI by using the standardized terms of the ACR BI-RADS MRI lexicon. The purpose is to familiarize all medical professionals with the breast MRI lexicon because the use of this imaging modality is rapidly growing in the field of breast disease. By using this common language, a comprehensive analysis of both morphological and kinetic features used in image interpretation will help radiologists and other clinicians to communicate more clearly and consistently. This may, in turn, help physicians and patients to jointly select an appropriate management protocol for each patient's clinical situation.

Diagnostic Breast MR Imaging: Current Status and Future Directions

Breast MRI has become an integral component in breast imaging. Indications have become clearer and better defined. Guidelines and recommendations are evolving and many are recognized and published. Future applications are exciting and may possibly improve our ability to diagnose breast cancer, improving the patient's treatment options and ultimately patient outcome.

The use of magnetic resonance imaging in breast cancer screening

Screening mammography is a powerful tool for reducing breast cancer mortality. Mammography can often detect clinically occult, early-stage breast cancer that is amenable to successful treatment. However, mammography is not a perfect test and has lower sensitivity in young women and in those with dense breasts. Magnetic resonance imaging (MRI) has been shown to depict breast cancers that are occult to other forms of detection, including mammography. This has generated interest in the use of MRI for breast cancer screening. Although preliminary studies in highly selected populations show promise for the potential efficacy of breast cancer screening with MRI, there are many questions that should be addressed before this technique is offered to the general population.

[Indications of MRI in the initial local staging of early-stage breast cancer]

MR Imaging is the most sensitive technique for detecting breast cancer. In patients with breast cancer, the additional value of MRI is validated in patients candidates for a breast-conserving surgery and when: cancer is occult, size evaluation is difficult at standard imaging, parietal involvement is suspected, and before neoadjuvant chemotherapy. In fatty breasts, MRI is not routinely recommended, because of same performances as in standard imaging. In dense breasts, MRI becomes significantly more sensitive than mammography for detecting multifocality and multicentricity with a positive predictive value of 60% for detected additional foci. Thus, a decision of mastectomy should not be made solely on the basis of MRI and may require additional tissue sampling of areas of concern identified by breast MRI. The additional value of breast MRI is particularly useful in patients with dense breasts and high risk factors for local recurrence: young age (< 40 years), familial high risk, or because of a high-grade invasive cancer greater than 2 cm in size. Performing breast MRI in such patients underlies requirements: an expert breast imaging team, optimal MRI protocols, and radiologists working in concert with the multidisciplinary treatment team.

Imaging breast cancer

Imaging has a significant role in diagnosing, treating, and monitoring breast cancer. Advances in this field are having a great impact in the clinical management of this disease. Breast cancer has now become an "outpatient cancer". This article describes the role and advances of imaging in breast cancer.

Breast MR imaging in assessing extent of disease

Breast MR imaging is valuable in assessment of extent of disease in the ipsilateral and contralateral breast in women who have breast cancer. In the ipsilateral breast, MR imaging depicts otherwise unsuspected sites of cancer in 16% (range, 6%-34%). In the contralateral breast, MR imaging depicts otherwise unsuspected sites of cancer in 6% (range, 3%-24%). MR imaging is most likely to depict additional sites of cancer in women with invasive lobular cancer and a family history of breast cancer. MR imaging can also assist in evaluating involvement of skin, pectoral muscle, and chest wall. Disadvantages of breast MR imaging include cost and additional procedures (follow-up and biopsy); furthermore, no data as yet show that breast MR imaging in the extend of disease evaluation improves disease-free or overall survival. If breast MR imaging is used in evaluating extent of disease, it is necessary to have the capability to perform biopsy of lesions detected by MR imaging only.

Preoperative MR Imaging in Patients with Breast Cancer: Preoperative Staging, Effects on Recurrence Rates, and Outcome Analysis

As well documented for other diseases (ie, lymphoma), an accurate pretherapeutic assessment of the extent of breast cancer is essential for planning the appropriate treatment to get the best long-term results, decrease recurrence rates, and increase patient survival. This article presents an overview of the effects of preoperative local staging with MR imaging in breast cancer patients.

MR Imaging in the Management of Patients with Breast Cancer

Magnetic resonance (MR) imaging has high sensitivity in detecting and determining the extent of breast cancer and the information provided by this modality has proven valuable in patient management. Investigations defining the strengths of MR imaging, technical advances, and greater standardization of protocols have led to its increased use in patients with breast cancer, both before and following treatment. This article reviews techniques and procedures used in the performance and interpretation of breast MR examinations. Applications of MR imaging in the management of patients with breast cancer are also summarized, including preoperative evaluation of extent of disease, postoperative assessment of residual disease, and the detection of recurrent carcinoma. The use of MR imaging to evaluate patient response to chemotherapy and to assess patients with axillary lymph node metastases with an unknown primary lesion will also be discussed.

Advances in breast imaging: magnetic resonance imaging

Magnetic resonance imaging (MRI) of the breast is rapidly becoming incorporated into clinical practice. Indications for breast MRI include staging of known breast cancer, monitoring response to chemotherapy, assessing recurrence, problem solving, and high-risk screening. Magnetic resonance spectroscopy is a promising technique that may decrease the number of benign biopsies generated by breast MRI in the clinical setting.

Prospective evaluation of pectoralis muscle invasion of breast cancer by MR imaging

BACKGROUND

Assessment of pectoralis muscle invasion is important for treatment planning for breast cancer. We evaluated the usefulness of breast magnetic resonance (MR) imaging for the detection of tumor invasion of the pectoralis muscle in breast cancer patients.

MATERIALS AND METHODS

A total of 306 breast MR examinations were performed preoperatively. Three-dimensional gradient echo sequences, at a section thickness of 1.5 or 2 mm were obtained with administration of gadolinium-DTPA. All patients underwent surgery.

RESULTS

In 33 breasts, disruption of the fat plane between tumor and muscle was noted. Seven of 33 cases showed muscle enhancement contiguous to enhanced tumors. Pathology reports indicated that 5 of 7 of the tumors involved muscle invasion. Of the 2 false positive cases, one showed muscle enhancement because of a previous biopsy, and the other was incorrectly interpreted as showing muscle enhancement. Of the 26 breasts which did not demonstrate muscle enhancement, none were found at surgery to have tumor involvement.

CONCLUSION

Enhancement of the pectoralis muscle correlates well with muscle invasion, but there are a few potential pitfalls. Disruption of the fat plane between tumor and muscle, without muscle enhancement, might not indicate tumor involvement of the pectoralis muscle.