Staging of symptomatic primary breast cancer with MR imaging

Reproducibility of the assessment of tumor extent in the breast using multiple image modalities

The accuracy of breast-conserving therapy (BCT) is limited by uncertainties in the assessment of tumor extent. These uncertainties may result in too wide treatment volumes leading to undesirable cosmetic results, or too narrow treatment volumes leading to higher probabilities of local recurrence. The aim of this study is to quantify the reproducibility of the assessment of tumor extent in the breast at preoperative diagnostic imaging with multiple imaging modalities and at pathology, applied to (1) determining minimum surgical safety margins to reduce the probability of underestimating the tumor extent due to uncertainty in the radiological assessment, and (2) defining the minimum difference between two measurements of tumor size that indicates a significant reduction of tumor extent in response to neoadjuvant chemotherapy or hormonal therapy. Measurements of the largest tumor diameter in mammography, ultrasonography, contrast-enhanced magnetic resonance imaging, and at pathology were retrieved, retrospectively, for 105 patients eligible for BCT. An analysis of variance technique is employed to separate uncertainty at preoperative diagnostic imaging from uncertainty at pathology. The random variations are thus calculated independently of the systematic deviations, avoiding the necessity to choose a gold standard. Moreover, the technique does not require repeat measurements of tumor extent, thus allowing the use of data that is obtained in daily clinical practice, while avoiding bias due to recollection. The magnitude of the random variations is used to determine minimum surgical safety margins and to define the minimum significant difference between two measurements of tumor size. The overall random variations in the assessment of tumor extent are on the order of 3 mm (1 s.d.) with only little differences of about 0.3 mm between the four techniques. The dependence of the random variations on tumor size was found significant (p < 0.05) for mammography (2.7 mm vs 4.2 mm, 1 s.d.) and ultrasonography (2.5 mm vs 3.8 mm, 1 s.d.) for tumors up to 17 mm compared to those that are larger. A minimum surgical safety margin on the order of 5 mm for tumors up to 17 mm and 7 mm for larger tumors takes the uncertainty in radiological assessment of the tumor extent into account effectively in 95% of the performed surgical procedures. A minimum difference in largest tumor diameter of 7 mm for tumors up to 17 mm and 9 mm for those that are larger indicates a significant (p < 0.05) reduction of tumor extent in response to neoadjuvant chemotherapy or hormonal therapy. The reproducibility of the assessment of tumor extent at preoperative diagnostic imaging is of comparable magnitude to the reproducibility at pathology. The uncertainty in the preoperative assessment of tumor extent constitutes a large portion (5-7 mm) of the current safety margin in breast-conserving surgery (10 mm). In monitoring response to neoadjuvant chemotherapy or hormonal therapy using repeat imaging before and after treatment, the current clinical guidelines may produce approximately 10% false-positive responses for tumors between 20 and 30 mm.

Simultaneous bilateral breast and high-resolution axillary MRI of patients with breast cancer: preliminary results

OBJECTIVE

The aims of this study were to develop a standardized one-step procedure for simultaneous high-resolution MRI of the axilla and bilateral breast MRI and to identify nodal features suggestive of metastatic involvement. SUBJECTS AND METHODS. We studied 16 women undergoing axillary lymph node dissection after combined bilateral breast MRI and high-resolution MRI of the axilla with a maximum in-plane resolution of 0.6 x 0.4 mm. MRI was performed using a standard double breast coil and a 15-cm round flexible surface coil adapted to the axilla. High-resolution axillary sequences, including inversion recovery T2- and spin-echo T1-weighted sequences, were performed before and after gadolinium chelates bolus injection. Axillary image analysis focused on nodal morphology including size, contour regularity, cortex and hilar appearance, signal intensity, and enhancement parameters. Axillary MRI findings were compared with the final pathogic results from axillary lymph node dissection in all patients. Patients were divided into groups according to the final pathologic axillary status. Differences in MRI lymph node features across the groups were tested using a t test for quantitative data and the chisquare test or Fisher's exact test for binary data.

RESULTS

The features of the axilla on high-resolution MRI that best discriminated between patients with positive pathologic findings and those with negative pathologic findings were the presence of nodes with irregular contours (p < 10(-4)), high signal intensity on T2 sequences (p < 10(-3)), marked gadolinium enhancement (p < 10(-3)), and round hila and abnormal cortexes (p < 0.05).

CONCLUSION

Breast tissue and axillary lymph nodes both can be analyzed on MRI in a one-step process using a bilateral breast coil combined with a surface coil. Morphologic features observed on high-resolution MRI of the axilla can improve the identification of metastatic nodes.

Preoperative breast MRI in patients with invasive lobular breast cancer

To investigate the use of MRI in preoperative characterization of invasive lobular breast cancer (ILC) and in detection of multifocal/multicentric disease. We retrospectively reviewed T1-weighted FLASH 3D precontrast and postcontrast MR images together with subtraction images of 26 women with histopathologically proven invasive lobular cancer. Two experienced radiologists described tumor patterns of ILC independently. MR findings of unifocal, multifocal, single quadrant and multiquadrant disease were correlated with results of other imaging techniques and compared with histopathological findings as gold standard. Most ILC presented on MRI as a single spiculated/irregular, inhomogeneous mass (pattern 1, n=12) or as a dominant lesion surrounded by multiple small enhancing foci (pattern 2, n=8). Multiple small enhancing foci with interconnecting enhancing strands (pattern 3) and an architectural distortion (pattern 4) were both described in three cases. There was one case of a focal area of inhomogeneous enhancement (pattern 5) and one normal MR examination (pattern 6). Unifocal and multifocal lesions were identified on MRI in four patients with normal conventional imaging. In nine women, multiple additional lesions or more extensive multiquadrant disease were correctly identified only on MRI. MRI may play an important role in the evaluation of patients with ILC, which is often difficult to diagnose on clinical examination and conventional imaging and more likely occur in multiple sites and in both breasts. However, false-negative MR findings do occur in a small percentage of ILC.

MRI before reexcision surgery in patients with breast cancer

OBJECTIVE

The aims of this study were to assess the diagnostic accuracy of MRI in evaluating patients for residual cancer, identify the prevalence of multicentric or multifocal disease, and evaluate the impact of MRI on surgical treatment planning. SUBJECTS AND METHODS. Of 101 potentially eligible patients, 80 candidates for breast conservation therapy who had primary breast cancer in 82 breasts diagnosed by excisional biopsy with close or positive margins were included in the study group. All patients underwent contrast-enhanced MRI before further surgery and subsequently underwent either reexcision lumpectomy or mastectomy with histopathologic correlation.

RESULTS

Residual carcinoma, either invasive or in situ, was present in 59.8% of the breasts. The sensitivity and specificity of MRI for detecting residual disease were 61.2% and 69.7%, respectively. Twenty-three additional lesions distant from the biopsy site were identified in 19 breasts, and 18 suspicious lesions underwent biopsy. Histology results indicated that six lesions were malignant, so the overall prevalence was 7.3%. The positive predictive value of identifying an additional suspicious lesion was 33.3%. In 24 breasts, MRI changed which procedure would be performed next from reexcision lumpectomy to mastectomy (n = 9), biopsy of an additional lesion in the ipsilateral (n = 12) or contralateral (n = 2) breast, or neoadjuvant chemotherapy (n = 1). Approximately 25% of the breasts underwent mastectomy as definitive surgical treatment.

CONCLUSION

Overlap in the appearances of benign and malignant lesions limits MRI evaluation for residual disease. MRI can show additional suspicious lesions that are likely to be multicentric or multifocal disease. These findings changed the original treatment plan for approximately 30% of breasts.

Imaging the lymphatic system: possibilities and clinical applications

The lymphatic system is anatomically complex and difficult to image. Lymph ducts are responsible for the drainage of part of the body's interstitial fluid. Lymph nodes account for the enrichment of lymph fluid, and can be involved in a large variety of diseases, especially cancer. For a long time, lymphatic imaging was limited to the sole use of conventional lymphography involving invasive procedures and patient discomfort. New contrast agents and techniques in ultrasound, nuclear medicine, and MR imaging are now available for imaging of both the lymphatic vessels and the lymph nodes. The objective of this review is to discuss the different imaging modalities of the lymphatic system, with a special focus on the new possibilities of lymphatic imaging including enhanced MR lymphography, sentinel node and positron emission tomography imaging, and contrast-enhanced ultrasound.

Locally advanced breast cancer: comparison of mammography, sonography and MR imaging in evaluation of residual disease in women receiving neoadjuvant chemotherapy

The accuracy of mammography, sonography and magnetic resonance imaging (MRI) in identifying residual disease after neoadjuvant chemotherapy is evaluated and imaging findings are correlated with pathologic findings. Fifteen patients enrolled in an experimental protocol of preoperative neoadjuvant chemotherapy underwent clinical examination, mammography, sonography and dynamic MRI, performed in this order, before and respectively after 2 and 4 cycles of neoadjuvant chemotherapy. Four radiologists, two for mammography, one for sonography and one for MR, examined the images, blinded to the results of the other examinations. All patients underwent radical or conservative surgery, and imaging findings were compared with pathologic findings. MRI identified 2/15 (13.3.%) clinically complete response (CR), 9/15 (60%) partial response (PR), 3/15 (20%) stable disease (SD) and 1/15 (6.7%) progressive disease. Mammography identified 1/15 (6.7%) clinically CR, 8/15 (53.3%) PR and 4/15 (27%) SD, and was not able to evaluate the disease in 2/15 (13%) cases. Sonography presented the same results as MRI. Therefore, MRI and sonography compared to mammography correctly identified residual disease in 100 vs. 86%. MRI resulted in two false-negative results because of the presence of microfoci of in situ ductal carcinoma (DCIS) and invasive lobular carcinoma (LCI). MRI was superior to mammography in cases of multifocal or multicentric disease (83 vs. 33%). Sonography performed after MRI improves the accuracy in evaluation of uncertain foci of multifocal disease seen on MR images with an increase of diagnostic accuracy from 73 to 84.5%. MRI assesses response to neoadjuvant chemotherapy better than traditional methods of physical examination and mammography.

Magnetic resonance imaging for preoperative evaluation of breast cancer: a comparative study with mammography and ultrasonography

BACKGROUND

The widespread use of mammographic screening has led to increased detection of small tumors that are often difficult to diagnose with conventional imaging modalities such as mammography and ultrasonography. Intraductal spread of breast cancer, a principle risk factor for local recurrence, is also difficult to diagnose with mammography and ultrasonography. We investigated the clinical usefulness of magnetic resonance imaging of the breast in the therapy of breast cancer and we compared it with mammography and ultrasonography.

STUDY DESIGN

A total of 183 patients with primary breast cancer underwent surgery at our institute between September 1, 1999, and November 30, 2002. They were examined preoperatively with magnetic resonance imaging, mammography, and ultrasonography. Magnetic resonance imaging evaluation included contrast-enhanced dynamic studies using IV injection of gadolinium-diethylenetriamine pentaacetic acid.

RESULTS

Detection rates of breast cancers by magnetic resonance imaging, mammography, and ultrasonography were 93.7%, 84.6%, and 97.3%, respectively (magnetic resonance imaging versus mammography, p < 0.05). Patterns of time-intensity curves in dynamic magnetic resonance imaging differed with histologic types. Sensitivity, specificity, and accuracy of detection of intraductal spread were 66.7%, 64.2%, and 65.6% with MRI; 22.2%, 85.7%, and 50% with mammography; and 20.6%, 85.2%, and 50% with ultrasonography, respectively (sensitivity, specificity, and accuracy; p < 0.05, respectively).

CONCLUSIONS

Magnetic resonance imaging can diagnose breast cancer as accurately as ultrasonography and more accurately than mammography. Patterns of time-intensity curves correlated with tumor histology. In addition, magnetic resonance imaging can detect intraductal spread more accurately than the other two methods. Magnetic resonance imaging appears to be indispensable in breast-conserving surgery to minimize local recurrence.

Diffusion-weighted Imaging of Breast Cancer with the Sensitivity Encoding Technique: Analysis of the Apparent Diffusion Coefficient Value

PURPOSE

The usefulness of diffusion-weighted imaging (DWI) in the field of neuroradiology has been established. Despite its high contrast resolution, DWI has the disadvantages of susceptibility artifact and chemical shift artifact. We performed DWI of breast cancer with the sensitivity encoding (SENSE) technique.

METHODS

The subjects were 60 female patients with breast mass. All patients underwent MRI including SENSE-DWI and were diagnosed histologically. Of these patients, 55 were diagnosed with breast cancer and the remaining five were diagnosed with benign mass. The histological diagnoses of breast cancer were as follows: 39 cases of invasive ductal carcinoma (IDC); 11 cases of IDC with a predominant intraductal component and non IDC (pure or predominant NIDC); and five cases of special types of cancer. The MR system used was a Gyroscan Intera 1.5T (Philips Medical Systems). In addition to routine MRI for breast cancer, including contrast-enhanced dynamic, SENSE-DWI was obtained. The accuracy of the positional information of SENSE-DWI was visually compared with that of conventional images. The apparent diffusion coefficient (ADC) values of breast mass were analyzed with SENSE-DWI.

RESULTS

The accuracy of positional information was adequate for diagnosing of all patients. The mean ADC value of breast cancer was 1.021x10(-3) mm2/s and that of benign mass was 1.488x10(-3) mm2/s (p=0.0002). The mean ADC value of IDC was 0.968x10(-3) mm2/s and that of pure or predominant NIDC was 1.218x10(-3) mm2/s (p=0.0011).

CONCLUSION

SENSE-DWI was of sufficient quality to support diagnosis of breast mass. SENSE-DWI may permit the acquisition of more detailed information about lesions, including tumor cellularity, that is difficult to obtain with conventional techniques.

O uso da ressonância magnética na investigação do câncer mamário

Os métodos diagnósticos de imagem mamografia, ultra-sonografia e cintilografia são exames imprescindíveis no diagnóstico do câncer de mama e no acompanhamento após o procedimento cirúrgico, porém, todos apresentam limitações específicas. Atualmente, a ressonância magnética tem-se revelado um método diagnóstico promissor para avaliar mais detalhadamente lesões tumorais do parênquima mamário. Neste trabalho os autores descrevem as principais indicações e os achados da ressonância magnética no câncer de mama, bem como comparam o seu desempenho com o dos outros métodos de imagem - mamografia, ultra-sonografia e cintilografia -, incluindo as vantagens e limitações de cada modalidade.

Minimally invasive surgery for small breast cancer

BACKGROUND AND METHODS

So-called minimally invasive techniques make percutaneous eradication of breast tumors possible, thus leading to breast-conserving treatment (BCT) without surgery. This paper reviews and discusses the feasibility of minimally invasive techniques for breast cancer.

RESULTS

Although a wide variety of ablation techniques have been investigated for the treatment of primary breast cancer, radiofrequency ablation (RFA) remains one of the most promising and potentially useful tools. RFA therapy results in effective cell killing in a predictable volume of tissue with a low complication rate. On the other hand, ultrasonography is useful for guiding the needle within the tumor but cannot predict the extent of thermal ablation accurately. Early post-procedural magnetic resonance imaging (MRI) may be useful for assessing whether complete tumor ablation has been achieved by RFA. Whether adequate ablation of the tumor has been achieved can be confirmed by extensive core needle sampling of the treated area. However, validation of the margin status is also important and this needs to be tackled in further studies.

CONCLUSIONS

There are many problems that remain before RFA therapy can be considered for conventional treatment. Further studies are needed to determine whether the use of RFA alone for local treatment of primary breast cancer will result in local recurrence and survival rates equivalent to those seen with BCT.

Outcome analysis and rational management of enhancing lesions incidentally detected on contrast-enhanced MRI of the breast

OBJECTIVE

The purpose of our study was to assess the prevalence, characteristics, and clinical consequence of incidentally detected enhancing lesions on MRI of the breast. SUBJECTS AND METHODS. MRI of the breast (1.0-T scanner, dynamic gadolinium-enhanced T1-weighted three-dimensional gradient-echo sequence, double breast coil) was performed on 1273 women for different indications. Enhancing incidental lesions were defined as enhancing lesions on MRIs that were not expected from findings on the previous conventional imaging. They were classified in five assessment categories using a scoring system based on morphologic and kinetic enhancement characteristics. Detection of enhancing incidental lesions resulted in a review of mammograms and sonograms with the aim of also localizing these lesions on conventional imaging. The lesions were either biopsied or followed up.

RESULTS

Twenty-five percent (274/1086) of all enhancing lesions detected in the study population were enhancing incidental lesions. Enhancing incidental lesions were found in 16% (210/1273) of all study patients. Forty-one percent (113/274) of the enhancing incidental lesions were histologically confirmed. Forty-eight percent (54/113) of the biopsied and 20% (54/274) of all enhancing incidental lesions were malignant. Eleven percent (54/508) of all malignant lesions occurring in the 1273 women were detected solely through additional MRI. Fifty-seven percent (31/54) of these MRI-detected malignant lesions could be identified on a reevaluation of sonograms and mammograms.

CONCLUSION

Detection of enhancing incidental lesions should lead to a thorough reevaluation of mammograms and sonograms. If not reidentified, suspicious enhancing incidental lesions should be biopsied, and enhancing incidental lesions that are probably benign should be carefully followed up. Indeterminate enhancing incidental lesions should be histologically examined by minimally invasive techniques or, if they are small, followed up by another MRI 6 months later.

Magnetic resonance imaging in patients diagnosed with ductal carcinoma-in-situ: value in the diagnosis of residual disease, occult invasion, and multicentricity

BACKGROUND

Although magnetic resonance imaging (MRI) has been shown to be a sensitive imaging tool for invasive breast cancers, its utility in ductal carcinoma-in-situ (DCIS) of the breast remains controversial. We studied the performance of MRI in patients with known DCIS for assessment of residual disease, occult invasion, and multicentricity to determine the clinical role of MRI in this setting.

METHODS

Fifty-one patients with biopsy-proven DCIS underwent contrast-enhanced MRI before surgical treatment. Pre-, early post-, and late postcontrast three-dimensional gradient echo images were obtained and MRI findings were correlated with histopathology. When possible, the performance of MRI and mammography was compared.

RESULTS

The accuracy of MRI was 88% in predicting residual disease, 82% in predicting invasive disease, and 90% in predicting multicentricity. The performance of MRI was equivalent in the core biopsy group when compared with the surgical biopsy group. For occult invasion only, MRI and mammography were equivalent. However, overall, MRI was more sensitive and had a higher negative predictive value than mammography.

CONCLUSIONS

MRI of DCIS can serve as a useful adjunct to mammography by providing a more accurate assessment of the extent of residual or multicentric disease. The performance of MRI is not significantly affected by antecedent surgical excision. MRI may be particularly valuable if preoperatively negative.

MR imaging of the ipsilateral breast in women with percutaneously proven breast cancer

OBJECTIVE

The purpose of this study was to review MR imaging findings in the ipsilateral breast in women with percutaneously proven breast cancer.

MATERIALS AND METHODS

Retrospective review was performed of records of 70 consecutive women with percutaneously proven unilateral breast cancer who were considered candidates for breast conservation surgery and who had preoperative MR imaging of the ipsilateral breast. MR images and medical records were reviewed.

RESULTS

MR imaging identified mammographically and clinically occult cancer other than the index lesion in the ipsilateral breast in 19 women (27%), including infiltrating cancer in 11 women (16%) and ductal carcinoma in situ in eight women (11%). These additional sites of cancer were in the same quadrant as the index cancer in 14 women (20%), in a different quadrant in three women (4%), and in both the same and different quadrants in two women (3%). Additional sites of cancer were more likely in women with, rather than in those without, a family history of breast cancer (42% vs 14%, p < 0.02) and in women whose index cancer was infiltrating lobular rather than other histologies (55% vs 22%, p < 0.06). In 17 women (24%), MR imaging detected ipsilateral lesions that were benign. Changes due to prior percutaneous biopsy were infrequently observed on MR images and included a clip in 12 women (17%) and a small hematoma in two women (3%).

CONCLUSION

MR imaging identified additional sites of ipsilateral cancer in 27% of women with percutaneously proven breast cancer. The yield was highest in women with a family history of breast cancer or infiltrating lobular histology in the index cancer. Change after biopsy was infrequent and did not interfere with the MR imaging interpretation.

The role of contrast-enhanced MR mammography for determining candidates for breast conservation surgery

PURPOSE

The aim of this study was to assess the impact of preoperative magnetic resonance mammography (MRM) on the surgical determination of breast conservation treatment for breast cancer patients.

METHODS

From September 1997 to March 2000, 57 consecutive breast conservation treatment candidates were prospectively evaluated with conventional imaging studies (mammography and ultrasonography) and preoperative MRM.

RESULTS

In 47 of 54 (87% ) breast cancer patients breast conservation surgery (BCS) was indicated on the basis of mammography (MMG) and ultrasonography (US). However in 40 of the 54 (74% ) patients BCS was indicated on the basis of MRM. Thirty-eight of the 40 patients ultimately underwent BCS and only 1 showed a positive margin. There were 7 patients whose MRM findings suggested that more aggressive treatment than BCS was needed but for whom US/MMG suggested that BCS was appropriate. Five of the 7 patients underwent mastectomy rather than BCS based on the MRM findings, which were justified by post-surgical histological findings. Of the 2 remaining patients who underwent BCS, one had a positive histological margin and one had recurrence, both of which resulted in salvage mastectomy.

CONCLUSION

Our study suggests that high resolution preoperative MRM provides more accurate information compared with US and MMG for selecting candidates for BCS. Using MRM as a routine staging tool may reduce unnecessary repeated excisions. A larger study will be required to confirm these findings and to define the patients most likely to benefit from breast MR imaging.

Preoperative assessment of breast cancer: sonography versus MR imaging

OBJECTIVE

The purposes of our study were to compare the diagnostic value of whole-breast sonography and MR imaging as adjunctive techniques to mammography and to determine whether MR imaging should be used routinely in the preoperative assessment of patients with suspected breast cancer.

SUBJECTS AND METHODS

. One hundred four women (age range, 34-84 years; mean age, 60 years) with findings highly suggestive of malignancy in the breast were examined with mammography, sonography, and dynamic MR imaging before undergoing surgery. All visualized suspicious lesions were correlated histologically. The diagnostic relevance of sonographic and MR imaging findings was compared with the diagnostic value of the findings of clinical examination and mammography alone.

RESULTS

. Twenty-seven tumors showed multifocal or multicentric invasive growth at pathology. Of these 27, 48% were correctly diagnosed via mammography alone; 63%, via the combination of mammography and sonography; and 81%, via MR imaging. Nine of the index tumors were invisible on mammography but were detected on sonography. Use of sonography benefited 13 patients and produced two studies with false-positive findings. Use of MR imaging benefited seven patients and produced eight studies with false-positive findings. In summary, 93% of all patients gained no advantage from MR imaging. Relevant additional findings were significantly more frequent in patients with dense breasts.

CONCLUSION

Although MR imaging is most sensitive for the detection of small tumors, routine preoperative MR imaging appears to be unnecessary for most patients if a combination of mammography and whole-breast sonography is used. Additional MR imaging can be restricted to problematic cases in women with dense breast parenchyma.

Preoperative breast cancer staging: MR imaging of the axilla with ultrasmall superparamagnetic iron oxide enhancement

PURPOSE

To evaluate magnetic resonance (MR) imaging with ultrasmall superparamagnetic iron oxide (USPIO) enhancement for preoperative axillary lymph node staging in patients with breast cancer by using histopathologic findings as the standard of reference.

MATERIALS AND METHODS

MR imaging was performed with a 1.5-T system within 24-36 hours after the start of intravenous slow-drip infusion of USPIO in 20 patients with breast cancer who were scheduled for surgery, followed by gadolinium-enhanced MR imaging. Lymph nodes were staged prospectively by using newly established criteria, and results were correlated with histologic findings.

RESULTS

In two patients, preoperative findings led to a change in therapeutic approach, and neoadjuvant chemotherapy was given; both patients were excluded from statistical analysis. Results of axillary staging with USPIO-enhanced MR imaging were true-positive in nine, true-negative in seven, false-positive in zero, and false-negative in two of 18 patients (sensitivity, 82%; specificity, 100%; positive predictive value, 100%; second reader, kappa = 1.0). Four hundred five lymph nodes were detected with MR imaging. For first and second readers, respectively, lymph node-based sensitivity was 83% and 73% and specificity was 96% and 97% (kappa = 0.68). USPIO as the intravascular contrast agent could not replace gadolinium for assessment of the primary tumor; however, no clinically relevant interaction was seen. Thus, an integrated imaging approach was feasible in all patients.

CONCLUSION

USPIO-enhanced MR imaging has the potential to become an adjunct to conventional MR imaging of the breast for preoperative assessment of axillary lymph nodes in patients with breast cancer.

Pre-operative staging of invasive breast cancer with MR mammography and/or PET: boon or bunk?

This study compared pre-operative staging with MR mammography (MRM) and positron emission tomography (PET) in patients with clinically suspected breast cancer according to the Breast Imaging Reporting and Data System, category 5. A total of 43 patients with breast cancer were examined. MRM included both T(2) weighted turbo spin echo sequences and T(1) weighted gradient echo sequences (three-dimensional fast low angle shot) before and after application of gadolinium-DPTA. All patients then underwent examination with a modern full-ring PET scanner following injection of fluorodeoxyglucose. We evaluated the efficacy of these methods in the diagnosis of primary tumour, contralateral carcinomas, bifocal, trifocal or multifocal disease, as well as non-invasive cancer portions and tumour size. Determination of patients' N-status was only attempted using PET. All findings were validated by histological examination. MRM was slightly superior to PET in several areas, such as in the respective methods' sensitivity and specificity. Sensitivities for MRM and PET were: 100% vs 93.0% in diagnosis of the primary tumour; 100% vs 100% in diagnosis of contralateral carcinomas; and 95.2% vs 92.5% in diagnosis of bifocal, trifocal or multifocal disease. Specificities for MRM and PET were: 100% vs 97.5% in diagnosis of contralateral carcinomas; and 96.8% vs 90.3% in diagnosis of bifocal, trifocal or multifocal disease. Non-invasive cancer portions and tumour sizes were equally well determined with both methods. The sensitivity of PET for detection of lymph node involvement was 80% and specificity 95%. MRM and PET were superior to conventional methods in nearly all areas studied; the findings of one or both of the methods impacted positively on patients' surgical treatment in 12.5-15% of cases. Pre-operative MRM and/or PET can have a positive influence on surgical treatment planning. Therefore, it appears useful to perform pre-operative staging with MRM or PET in these patients.

Sentinel node biopsy: an in depth appraisal

Sentinel node biopsy (SNB) in primary breast cancer has been taken-up widely to avoid the morbidity attributable to axillary node clearance (ANC). Currently many issues surrounding SNB are undecided. This review summarises why some form of axillary surgery is required and presents data on all aspects of SNB including methodology, clinical results and problems that may delay the introduction of SNB as best practice for all patients with primary breast cancer. There is no long or medium term data relating to the consequences of replacing ANC with SNB, but the mechanisms and probable magnitude of both beneficial and detrimental effects are estimated. A low level of false negative results are inherent to the technique but it is demonstrated that SNB is likely to have an only marginal (0.6%) effect on survival that would be undetectable by clinical trials. Patient sub-groups particularly likely to benefit from SNB are identified.

Feasibility of MR imaging-guided breast lumpectomy for malignant tumors in a 0.5-T open-configuration MR imaging system

RATIONALE AND OBJECTIVES

The authors performed this study to develop the technology for and evaluate the utility of a 0.5-T vertical open-configuration magnetic resonance (MR) imaging system for imaging-guided breast lumpectomy of malignant tumors.

MATERIALS AND METHODS

Twenty women with breast cancer underwent MR imaging-guided lumpectomy in a 0.5-T vertical open-configuration MR system. During lumpectomy, pre- and postresection images were acquired with and without contrast material. Images were used both for tumor localization and to monitor resection. If residual enhancement was observed, additional resection was performed in an effort to secure negative pathologic margins.

RESULTS

The procedure evolved over time with technology innovations and improvements. Specifically, instruments were acquired that were compatible with MR imaging breast procedures, the echo time with the Dixon technique was modified to optimize image quality, contrast material injection was timed for maximum lesion enhancement, breath-hold image acquisition was instituted, and the biopsy cavity was filled with saline and the incision closed before image acquisition.

CONCLUSION

All breast lesions were identified despite limited spatial resolution and fat-suppression techniques. The evolved techniques facilitated intraoperative margin evaluation and prompted additional surgical margin resection in five patients, sparing four from an additional surgical procedure. Intraoperative MR imaging has the potential to improve the complete pathologic excision of invasive breast cancer.

MR imaging-detected breast lesions: histopathologic correlation of lesion characteristics and signal intensity data

OBJECTIVE

The aim of our study was to differentiate benign from malignant breast lesions that had been detected exclusively on MR imaging by analyzing qualitative and quantitative lesion characteristics.

MATERIALS AND METHODS

We performed 51 MR imaging-guided breast interventions (41 preoperative lesion localizations and 10 large-core needle biopsies) in 45 patients with exclusively MR imaging-detected lesions. All patients had previously undergone diagnostic dynamic contrast-enhanced MR imaging of the breast with a double breast coil at 1.0 T (n = 36) or 1.5 T (n = 15). The diagnostic MR images were evaluated on a workstation. Lesion morphology (size, shape, margin type, enhancement pattern), signal intensity parameters (time to peak enhancement, maximum slope of enhancement curve, washout, relative water content), and scores analogous to the Breast Imaging Reporting and Data System (BI-RADS) categories were correlated with histology.

RESULTS

Histology revealed malignancy in 37.3% (19/51) of the lesions. The positive predictive value for malignancy of exclusively MR imaging-detectable lesions increased as the analogous BI-RADS category increased. Late inhomogeneous contrast enhancement was the only morphologic criterion that was statistically significantly correlated with malignancy. Malignant and benign lesions did not differ significantly in any of the quantitatively evaluated signal intensity parameters. Carcinomas showed a tendency toward faster and stronger enhancement and stronger washout.

CONCLUSION

The classification of exclusively MR imaging-detectable breast lesions according to a combination of morphologic and perfusion parameters including the late enhancement pattern helps identify the lesions for which interventional MR imaging is required. Quantitative signal intensity data alone do not suffice.

Breast cancer imaging with MRI

Breast MRI is an emerging technology that may revolutionize our management of women with known or suspected breast cancer. MRI examinations should be interpreted with an awareness of the pitfalls and artifacts that can affect on image evaluation. Development of an MRI lexicon will assist by providing standardized terminology that may improve our understanding of the positive predictive value of different MRI features. To date, breast MRI has proven most useful in patients with proven breast cancer to assess for multifocal/multicentric disease, chest wall involvement, chemotherapy response, or tumor recurrence or to identify the primary site in patients with occult breast cancer. Further work is necessary to assess the utility of breast MRI in other settings, such as screening of women at high risk for breast cancer.

Occult contralateral breast carcinoma incidentally detected by breast magnetic resonance imaging

The incidence of synchronous bilateral breast cancers has been reported to be between 3.4% and 7.4%, as detected on mammography, physical examination, or both. We undertook a study to determine how often magnetic resonance (MR) imaging detects a contralateral abnormality in patients with known breast carcinoma. As part of an institutional review board (IRB) -approved research protocol, 17 patients with pathologically proven invasive carcinoma underwent preoperative MR imaging of both breasts using a T1-weighted, high-resolution gradient echo sequence (precontrast and postcontrast), an echo-planar sequence during administration of gadolinium, and a T2-weighted, fast-spin echo sequence. The morphology and dynamic enhancement of lesions in both breasts were assessed. Biopsy was recommended for any lesion meeting set criteria. MR imaging identified all 17 known invasive cancers in the breast of concern on mammography or physical examination. Five of 17 patients (29%) had 10 contralateral lesions identified on MR, for which biopsy was recommended. One of these lesions proved to represent a fibroadenoma. The other 9 lesions proved to represent a malignancy (6 invasive lobular, 2 infiltrating ductal, and 1 tubular). Four of the 17 patients (24%) with invasive cancer had contralateral synchronous cancers occult to physical examination, mammography, and ultrasonography. In this series, breast MR imaging of the breasts was more sensitive than mammography or physical examination in the detection of early breast cancer. Breast MR imaging of the contralateral breast may be of value as a routine screen in those patients with a known or suspected malignancy.

Minimally invasive therapy for the treatment of breast tumours

Minimally invasive therapy has been explored as a potential means of treating breast tumours with minimal disruption to adjacent soft tissues. The purpose of this is to facilitate improved cosmesis and to offer treatment to women who are unfit for surgery. A number of treatment modalities including thermal therapies (intersitital laser photocoagulation, radiofrequency, focused ultrasound and cryotherapy), percutaneous excision and interstitial radiotherapy are being developed. The experience to date of each of these modalities is described and reviewed. Currently there are too few data to indicate the efficacy of these treatments although the preliminary data are encouraging. The need for large-scale studies examining the role of MIT in relationship to the overall management of breast cancer (including chemotherapy, radiotherapy, and the management of the axilla) and outcome is discussed.

Staging of palpable T1-2 invasive breast cancer with helical CT

BACKGROUND

The purpose of this study was to evaluate the accuracy of contrast-enhanced high resolution helical computed tomography (CT) for assessing locoregional staging of palpable T1-2 invasive breast cancer.

METHODS

Helical CT studies of 156 lesions from 156 patients with invasive breast cancer before breast-conserving surgery were examined. A lesion was defined as positive if focal enhancement was detected by CT within 100 seconds after contrast material administration. After resection, tumors were histopathologically mapped and comparison made with the extent of contrast enhancement.

RESULTS

Helical CT enabled detection of all 156 index tumors. CT enabled detection of 28 of 43 multifocal lesions (65%) and five of five multicentric lesions (100%). In 24 of 33 lesions (73%), CT revealed additional cancers not seen on mammography. The extent of tumor significantly correlated with CT measurements (r=0.76, p<0.0001).

CONCLUSION

Helical CT of the breast is an accurate preoperative imaging modality for assessing the locoregional staging of T1-2 invasive breast cancer.

Dynamic contrast-enhanced MRI studies in oncology with an emphasis on quantification, validation and human studies

Magnetic resonance imaging (MRI), after the administration of an extracellular, gadolinium-based contrast medium, can be used to detect and characterize human tumours. The success of dynamic contrast-enhanced MRI (DCE-MRI) is dependent on its ability to demonstrate intrinsic differences between a variety of tissues that affect contrast medium behaviour. Evidence is mounting that DCE-MRI measurements correlate with immunohistochemical surrogates of tumour angiogenesis. DCE-MRI can monitor the effectiveness of a variety of treatments including chemotherapy, hormonal manipulation, radiotherapy and novel therapeutic approaches including antiangiogenic drugs. Kinetic parameters in the treatment setting have been correlated with histopathological outcome and patient survival. This article reviews quantification analysis of these studies together with current and future clinical applications.

MR imaging of the breast for the detection, diagnosis, and staging of breast cancer

With the introduction of contrast agents, advances in surface coil technology, and development of new imaging protocols, contrast agent-enhanced magnetic resonance (MR) imaging has emerged as a promising modality for detection, diagnosis, and staging of breast cancer. The reported sensitivity of MR imaging for the visualization of invasive cancer has approached 100%. There are many examples in the literature of MR imaging--demonstrated mammographically, sonographically, and clinically occult breast cancer. Often, breast cancer detected on MR images has resulted in a change in patient care. Despite these results, there are many unresolved issues, including no defined standard technique for contrast-enhanced breast MR imaging, no standard interpretation criteria for evaluating such studies, no consensus on what constitutes clinically important enhancement, and no clearly defined clinical indications for the use of MR imaging. Furthermore, this technology remains costly, and issues of cost-effectiveness and cost competition from percutaneous biopsy have yet to be fully addressed. These factors along with the lack of commercially available MR imaging--guided localization and biopsy systems have slowed the transfer of this imaging technology from research centers to clinical breast imaging practices. Technical requirements, potential clinical applications, and potential pitfalls and limitations of contrast-enhanced MR imaging as a method to help detect, diagnose, and stage breast cancer will be described.

MRI: a role in clinical trials

The diagnosis and treatment of breast cancer has evolved significantly over the last 20 years. Breast-conserving therapy is replacing the Halstedian concept of "en bloc" resection. Difficulties in detection, pre- and postoperative planning and follow up continue to challenge the clinician. Women at high risk present a significant clinical dilemma. MRI technology in many of these areas is providing more information about detection, tumor size, extent, and response to treatment. The careful and thoughtful inclusion of MRI in clinical trials may help continue the advancement of breast cancer care. J. Magn. Reson. Imaging 2001;13:837-841.

MRI vs. histologic measurement of breast cancer following chemotherapy: comparison with x-ray mammography and palpation

Twenty consecutive patients with breast cancer were evaluated following chemotherapy using MRI to assess the size of cancer residua and compare these data with subsequent histologic measurements of the viable tumor. This retrospective study also involved assessment of the preoperative size of the malignancy as determined by physical exam and x-ray mammogram. These values were later compared with the histology. The tumor size correlation coefficient between MRI and pathologic analysis was the highest, at 0.93. Physical exam and x-ray mammography (available for 17 patients) produced correlation coefficients of 0.72 and 0.63, respectively, compared to histologic measurement. The accuracy of MRI did not vary with the size of cancer residua. MRI is an accurate method for preoperative assessment of breast cancer residua following chemotherapy. J. Magn. Reson. Imaging 2001;13:868-875.

MR imaging: breast cancer staging and screening

This review describes the current knowledge and challenges of breast cancer staging and screening with MRI of the breast. Assessment of local disease extent, including tumor size, multicentricity, and chest wall invasion, can be obtained more accurately with MRI than with mammography. Moreover, international experts have established standardized reporting of MRI staging results, taking into account tumor size measurements and the number of breast quadrants involved. Results from MRI assessment of the axilla and skin are promising, but need further refinement. Preliminary results of the use of breast MRI in patients at high risk for breast cancer demonstrated a superiority of breast MRI over the combined use of mammography and high-frequency ultrasound. The role of MRI in this subset of patients may be confirmed by ongoing larger multicenter trials. Strict protocol conditions are mandatory to maintain a high standard of quality. Confirming the nature of "MRI-only" lesions with MRI-guided biopsy systems will allow changes in treatment planning. More accurate tumor diagnosis and tumor volume evaluation may allow minimally invasive treatment strategies.

In vitro high-resolution helical CT of small axillary lymph nodes in patients with breast cancer: correlation of CT and histology

OBJECTIVE

This study seeks to determine whether high-resolution in vitro helical CT can show the internal structure of small axillary nodes and to establish the CT characteristics of benign versus metastatic axillary nodes in patients with breast cancer.

SUBJECTS AND METHODS

We obtained in vitro helical CT images of 212 nodes excised from 19 patients with breast cancer. The longest mean size was 5.9 mm, and the range was 0.5 to 26.5 mm. The hilar and cortical characteristics, the size, and the ratio of the longest axis to the shortest axis were evaluated. CT findings were correlated with histologic findings.

RESULTS

Pathologic assessment of excised nodes with a central low-density hilum visualized on CT showed arteries, veins, lymphatic sinuses, and fatty tissue. A peripheral high-density cortex on CT contained mostly lymphatic tissue. Abnormal (eccentric, irregular) cortices were observed in malignant nodes (p<0.0001). Marked differences were observed among the proportions of benign and malignant nodes when the ratio of the longest axis to the shortest axis was less than 2 and an abnormal cortex was observed. CT could also detect extracapsular lymph node extension.

CONCLUSION

In vitro high-resolution helical CT can detect the internal structure of small nodes. Morphologic changes detected on helical CT help distinguish benign from malignant nodes.

MR imaging of the breast in patients with invasive lobular carcinoma

OBJECTIVE

Our objective was to assess the usefulness of MR imaging in patients diagnosed with invasive lobular carcinoma of the breast.

MATERIALS AND METHODS

Between July 1993 and September 1999, 32 women (33 cases) diagnosed with pure invasive lobular carcinoma of the breast underwent contrast-enhanced MR imaging examination. One woman was excluded because of lack of follow-up. Correlation was made between the mammographic and sonographic findings, the MR imaging findings, and the final pathology results for the remaining 32 cases.

RESULTS

In 18 women who did not undergo excisional biopsy before the MR imaging, MR imaging showed more extensive tumor burden or the detection of the primary lesion that was occult on conventional imaging in seven (38.9%) of 18 women. In nine (50%) of 18 women, MR imaging performed equally as well as mammography and sonography. In one case (5.6%), MR imaging and mammography underestimated disease extent. In another patient (5.6%), MR imaging overestimated tumor burden, although mammography failed to show the cancer. In 14 patients who had excisional biopsy before the MR imaging, residual tumor was shown in eight women (57.1%) with extensive tumor or additional separate foci in five of the eight patients. In two cases (14.3%) that were interpreted as equivocal, residual tumor was shown in both cases on reexcision. In three cases (21.4%), the MR imaging was interpreted as negative, but microscopic tumor was shown around seroma on reexcision. False-positive enhancement was seen in one case (7.1%).

CONCLUSION

MR imaging showed more extensive tumor than conventional imaging and affected the clinical management in 16 (50%) of 32 patients with invasive lobular carcinoma.

MRI-guided needle localization: technique

Magnetic resonance imaging (MRI) is being used increasingly in breast cancer diagnosis. Such indications include the search for a breast primary in women with metastatic carcinoma in the axillary lymph nodes, improving surgical planning in women with a biopsy-proven breast cancer, and in screening very high-risk women. If a suspicious lesion is found by MRI, localization with either directed additional mammographic or sonographic views or with MRI-guided needle localization or biopsy is necessary. We describe the use of a biopsy device with embedded internal fiducial markers. The coordinates for needle placement are calculated by distances between the fiducial markers and the lesion. The technique is simple to master and is aided by the use of a practice phantom.

Imaging of axillary lymph nodes

There is increasing interest in the radiological diagnosis of axillary lymph nodes in patients with breast cancer, especially in the preoperative diagnosis of metastatic nodes. Both CT (computed tomography) and MRI (magnetic resonance imaging) are cross-sectional imaging methods that produce high-quality images of the axilla. MRI also uses contrast enhancement profile, for example in imaging of breast lesions. Few studies have been published on this subject, but the latest have shown high sensitivity and specificity (CT 93.8 and 82.1%, respectively; MRI 90 and 82%, respectively), although, both CT and MRI are restricted to imaging only. US (ultrasound) is widely spread and is fast and accurate with high resolution. Sensitivity and specificity vary (68.2-92% and 90-100%, respectively). Most importantly, there is the possibility of US-guided FNAB (fine-needle aspiration biopsy) of pathological nodes, which increases the specificity. Initial results with colour Doppler are promising, but a recent study has shown that the presence of colour Doppler flow signal is highly non-specific. Other parameters such as flow pattern and distribution may prove to be of value in this method. Today, the method of choice for the daily routine is US in conjunction with FNAB.

MR imaging of the breast

The results of clinical investigation suggest that MR imaging can provide clinically important information that cannot be obtained with conventional imaging methods, and that this modality will, in the future, be an invaluable adjunctive breast imaging tool just as breast ultrasound is today. MR imaging appears to be the most accurate method for the detection of implant failure, and although it is the most costly of the available implant imaging techniques, it may be the study of choice when there is a question of implant integrity that cannot be answered with conventional methods. MR imaging as a method to detect, diagnose, and stage breast cancer remains in the investigational stage. The specificity of MR imaging appears limited because of the overlap in the enhancement kinetics and morphologic appearance of benign and malignant lesions. In selected cases, the identification of certain morphologic features, such as internal septations or the absence of enhancement, may be used to classify a lesion as benign, offering an alternative to percutaneous or excisional biopsy. MR imaging appears to be very sensitive for the visualization of both invasive carcinoma and DCIS. Perhaps most important, MR imaging can detect invasive and noninvasive breast carcinoma that is both mammographically and clinically occult, offering the potential for more accurate breast cancer staging and optimized treatment planning. MR imaging is emerging as perhaps the most promising imaging modality for breast cancer detection to date. Published results, however, are from studies with relatively small numbers of patients. The results of these studies should be validated in a large-scale clinical trial before MR imaging is implemented clinically, outside of research settings. This type of clinical investigation is needed to define the technical requirements for optimal imaging, to define interpretation criteria, to develop accurate MR imaging guided localization and biopsy systems, to define the clinical indications for which MR imaging should be used as an adjunct to conventional imaging methods, and to address the issue of cost-effectiveness. One such trial, an international, multi-institutional study funded by the National Cancer Institute, is presently underway.

Breast imaging: from 1965 to the present

The current state of the art for breast imaging is reviewed in comparison with the methods of practice commonly in use 25-35 years ago to demonstrate the most important advances that have taken place in imaging techniques, operational considerations, interpretive approaches, and interventional procedures. Since 1965, breast imaging has progressed from the simple assessment of breast disease in a selected small number of symptomatic women to the comprehensive evaluation of both breast health and disease in a substantial percentage of all women aged 40 years and older. In the process, breast imaging has become an established radiologic subspecialty that accounts for at least 10% of all examinations performed by radiologists. Indeed, mammography now is the most common imaging examination that directly results in the reduction of mortality from disease.

The Diagnosis and Treatment of Ductal Carcinoma In Situ of the Breast

Ductal carcinoma in situ of the breast is the most favorable presentation of breast cancer; therefore appropriate local treatment is imperative. Intraductal carcinoma is being diagnosed more frequently with the increasing use of screening mammography. A number of pathologic features have been identified which are useful for classification and for prognostic information. In addition, the molecular pathology and its relationship to tumor behavior and prognosis is becoming more well understood. The role of axillary dissection has been examined in a number of series and is generally agreed to be unnecessary for this presentation of breast cancer, allowing many women to avoid the sequela of axillary surgery. This review discusses the use of breast conservation treatment and the evolving indications for excision alone in the treatment of ductal carcinoma in situ. The outcomes for breast conservation therapy from both randomized trials and institutional series have confirmed excellent survival rates. Salvage therapy for local recurrence is frequently successful, resulting in nearly equivalent survivals in women undergoing breast conservation therapy compared to mastectomy. In addition, intriguing but preliminary results from both breast cancer prevention studies and trials looking at the use of tamoxifen for intraductal cancer suggest a local control benefit in women using the drug.

Breast carcinoma: effect of preoperative contrast-enhanced MR imaging on the therapeutic approach

PURPOSE

To determine if magnetic resonance (MR) imaging can help determine the therapeutic approach in women with breast cancer.

MATERIALS AND METHODS

Preoperative contrast-enhanced MR imaging of the breast was performed in 463 patients with probably benign lesions (n = 63), suspicious lesions (n = 230), or lesions highly suggestive of malignancy (n = 170) per established clinical, mammographic, and/or ultrasonographic (US) criteria. T1-weighted fast low-angle shot MR imaging was performed before and after administration of gadopenetetate dimeglumine. MR imaging findings were correlated with other imaging results and histopathologic findings. Special attention was paid to multifocality and multicentricity.

RESULTS

Histopathologic analysis revealed 143 benign and 405 malignant lesions. The sensitivity, specificity, and accuracy were 58%, 76%, and 62% for clinical examination; 86%, 32%, and 72% for conventional mammography; 75%, 80%, and 76% for US; and 93%, 65%, and 85% for contrast-enhanced MR imaging. Multifocality in 30 of 42 patients, multicentricity in 24 of 50 patients, and additional contralateral carcinomas in 15 of 19 patients were depicted with MR imaging alone. Due to the MR imaging findings, therapy was changed correctly in 66 patients (14.3%); unnecessary open biopsy was performed in 16 patients (3.5%).

CONCLUSION

Contrast-enhanced MR imaging of the breast is highly sensitive for invasive breast cancer. MR imaging may reveal unsuspected multifocal, multicentric, or contralateral breast carcinoma and result in therapy changes.

Dynamic contrast enhanced magnetic resonance imaging of the breast is superior to triple assessment for the pre-operative detection of multifocal breast cancer

BACKGROUND

Inadequately treated multifocal and multicentric disease results in increased local recurrence following breast-conserving surgery. The accurate preoperative diagnosis of multifocal/ centric breast cancer would facilitate the planning of appropriate surgery and prevent reoperation for residual disease. While triple assessment remains the established diagnostic technique, its sensitivity for the diagnosis of multifocal disease remains poor. Dynamic contrast enhanced Magnetic Resonance Imaging (DCE-MRI) of the breast represents an alternative emerging diagnostic modality that has been shown to be highly sensitive for the delineation of primary breast cancer. The aim of this study was to prospectively compare the diagnostic accuracy of DCE-MRI of the breast with conventional triple assessment for the preoperative diagnosis of multifocal/centric breast cancer.

METHODS

Patients were recruited from the symptomatic breast clinics. All patients underwent standard triple assessment and DCE-MRI. The MRI scans were reported by a single radiologist blinded to the results of the triple assessment. Surgery was then planned accordingly to all available scan results and the specimens examined by a single pathologist. All patients who did not undergo surgery have been followed up for a minimum of 18 months.

RESULTS

A total of 334 women were recruited. There were 178 (52%) cancers that were histologically confirmed and multifocal/centric breast cancer was diagnosed provisionally by the preoperative investigations in 68 (38%); multifocal n = 33, multicentric n = 35, of these patients. In this group, subsequent histology confirmed multifocal/centric disease in 50 (73.5%): multifocal n = 15, multicentric n = 35. Unifocal cancer was found in 15 (22%) and benign disease in 3 (4.4%). The resultant sensitivity, specificity, positive, and negative predictive values were 18%, 100%, 100%, and 76% for triple assessment and 100%, 86%, 73%, and 100% for DCE-MRI.

CONCLUSION

DCE-MRI identified a subgroup of breast cancer patients with multifocal/centric disease not evident on standard triple assessment. MRI of the breast should be considered for the preoperative planning of surgery for primary breast cancer.

Breast MR imaging in patients with axillary node metastases and unknown primary malignancy

PURPOSE

To assess the usefulness of magnetic resonance (MR) imaging of the breast in patients with malignant axillary adenopathy and unknown primary malignancy.

MATERIALS AND METHODS

Between October 1993 and December 1997, 38 women with malignant axillary adenopathy and negative mammographic and physical examination findings underwent contrast material-enhanced MR imaging. Sixteen patients were excluded due to axillary tail cancer (n = 7), lack of follow-up (n = 4), second primary malignancy (n = 3), or chemotherapy before MR imaging (n = 2). The study population comprised the remaining 22 patients. Histopathologic findings were available in 20 patients; follow-up MR imaging findings were available in two patients.

RESULTS

MR imaging depicted a primary breast cancer in 19 patients (86%; identified at excisional biopsy or mastectomy in 17, resolved on follow-up MR images during treatment in two). MR imaging depicted 4-30-mm cancers (mean, 17 mm), which correlated closely with histopathologic size. Two patients (9%) had false-negative findings: (a) One had a 2-mm invasive ductal carcinoma, and (b) one had 17- and 20-mm invasive ductal carcinomas. Of the 19 patients, 11 underwent mastectomy, seven underwent breast-conservation therapy, and one did not undergo a surgical procedure.

CONCLUSION

MR imaging is very sensitive for the detection of mammographically and clinically occult breast cancer in patients with malignant axillary adenopathy. In these patients, MR imaging offers potential not only for cancer detection but also for staging the cancer within the breast, which may be useful for treatment planning.

Advances in breast imaging

Many exciting developments are occurring in breast imaging. Digital mammography holds the promise of telemammography and computer-aided diagnosis. Mammoscintigraphy may be helpful in identifying drug-resistant tumors before therapy. There is renewed interest in evaluating ultrasound as a potential adjunctive screening tool in women with radiographically dense breasts. Finally, contrast-enhanced magnetic resonance imaging may be used more extensively in the monitoring of tumor response to primary chemotherapy and in the preoperative workup of patients being considered for breast conservation therapy.

Lymphatic mapping and sentinel node biopsy in breast cancer

BACKGROUND

Sentinel lymph node biopsy is a recently developed, minimally invasive technique for staging the axilla in patients with breast cancer. It has been suggested that this technique will avoid the morbidity associated with more extensive axillary dissection. A wide range of different methods and materials has been employed for lymphatic mapping, but there has been little consensus on the most reliable and reproducible technique.

METHODS

This is a comprehensive review of all published literature on sentinel node biopsy in breast cancer, using the Medline and Embase databases and cross-referencing of major articles on the subject.

RESULTS AND CONCLUSION

Sentinel node biopsy is a valid technique in breast cancer management, providing valuable axillary staging information. The optimal technique of lymphatic mapping utilizes a combination of vital blue dye and radiolabelled colloid. However, there remain controversial issues which require to be resolved before sentinel node biopsy becomes a widely accepted part of breast cancer care.