Locally advanced breast cancer: contrast-enhanced subtraction MR imaging of response to preoperative chemotherapy

Quimioterapia primária em câncer de mama localmente avançado: Estudo comparativo entre dois esquemas terapêuticos com intensificação de doses

Realizou-se um estudo clínico prospectivo, fase III, multicêntrico, aberto, aleatório e comparativo. Foram avaliadas 60 pacientes portadoras de câncer de mama localmente avançado, estádio IIIA, divididas em dois grupos. As pacientes foram submetidas à quimioterapia primária, com ou sem intensificação de dose, por quatro ciclos, e à cirurgia. Utilizou-se o protocolo FEC 50 no Grupo A (5-FU 500 mg/m2, epirubicina 50 mg/m2 e ciclofosfamida 500 mg/m2) e o FEC 100 no Grupo B (5-FU 500 mg/m2, epirubicina 100 mg/m2 e ciclofosfamida 500 mg/m2). Foram analisados, durante a quimioterapia, o estado geral, variação ponderai, alopécia, alterações digestivas, hematológicas e cardiotoxicidade. Após a quimioterapia avaliou-se a resposta tumoral clínica e, na peça cirúrgica, a resposta anatomopatológica. A resposta clínica objetiva (resposta completa e resposta parcial) nos grupos A e B foi 93% e 96%, respectivamente. Os resultados foram similares, porém no Grupo B houve um percentual maior de respostas clínicas completas. Avaliou-se a doença residual no sítio primário e nos linfonodos axilares. No Grupo A houve 4 (13%) casos de resposta anatomopatológica completa, 12 (40%) de tumor residual microscópico e 14 (47%) de tumor macroscópico. No Grupo B ocorreram 10 (33%) casos de resposta anatomopatológica completa, sete (23%) de tumor residual microscópico e 13 (44%) de tumor macroscópico. Concluiu-se que a quimioterapia primária proporcionou resposta clínica e anatomopatológica maior no grupo com intensificação de dose. A toxicidade, tolerável e reversível, foi mais acentuada no grupo de altas doses.

The clinical value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) semi-quantitative parameters in monitoring neoadjuvant chemotherapy response of osteosarcoma

BACKGROUND

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is a non-invasive technique which could monitor tumor morphology, blood vessel dynamics, and micro-environmental changes.

PURPOSE

To evaluate the value of DCE-MRI semi-quantitative parameters in monitoring the neoadjuvant chemotherapy (NAC) response of osteosarcoma.

MATERIAL AND METHODS

Twenty-five patients pathologically confirmed as osteosarcoma received four cycles of NAC followed by surgery. All patients underwent conventional and dynamic MRI twice, before starting chemotherapy and before surgical treatment. With a reference standard of histological response (tumor necrosis rate), semi-quantitative parameters were compared between good response group (TNR ≥ 90%) and non-response group (TNR < 90%). The differences between intra- and inter-group parameters before and after NAC were analyzed by Mann-Whitney U test. Receiver operating characteristic (ROC) analysis was generated to assess the parameters' efficacy in predicting the outcome of NAC.

RESULTS

The changes were statistically significant on slope, maximum signal intensity (SI_max), time to peak (TTP), signal enhanced extent (SEE), peak percent enhancement (PPE), washout rate (WOR), and enhancement rate (ER) in the good response group (P < 0.05), while only SI_max and SEE were different in the non-response group after NAC. The changes in Slope, SI_max, TTP, SEE, WOR, and ER were markedly different (P < 0.05) between the two groups after NAC. Also, at the threshold values of 3.2%/s, 175 s, and 5.4% (slope, TTP, and ER), the sensitivity and specificity for predicting good response to chemotherapy were 83.3% and 92.3%, 91.7% and 69.2%, 84.6% and 75.0%, respectively.

CONCLUSION

Slope, TTP, and ER values could be used to evaluate and predict the response to NAC in osteosarcoma.

Contrast-enhanced Mammography: A Guide to Setting Up a New Clinical Program

Contrast-enhanced mammography (CEM) is gaining rapid traction following the U.S. Food and Drug Administration approval for diagnostic indications. Contrast-enhanced mammography is an alternative form of mammography that uses a dual-energy technique for image acquisition after the intravenous administration of iodinated contrast material. The resulting exam includes a dual set of images, one that appears similar to a routine 2D mammogram and one that highlights areas of contrast uptake. Studies have shown improved sensitivity compared to mammography and similar performance to contrast-enhanced breast MRI. As radiology groups incorporate CEM into clinical practice they must first select the indications for which CEM will be used. Many practices initially use CEM as an MRI alternative or in cases recommended for biopsy. Practices should then define the CEM clinical workflow and patient selection to include ordering, scheduling, contrast safety screening, and managing imaging on the day of the exam. The main equipment requirements for performing CEM include CEM-capable mammography equipment, a power injector for contrast administration, and imaging-viewing capability. The main staffing requirements include personnel to place the intravenous line, perform the CEM exam, and interpret the CEM. To safely and appropriately perform CEM, staff must be trained in their respective roles and to manage potential contrast-related events. Lastly, informing referring colleagues and patients of CEM through marketing campaigns is helpful for successful implementation.

Comparison of postoperative CT- and preoperative MRI-based breast tumor bed contours in prone position for radiotherapy after breast-conserving surgery

Objectives

To compare the target volume of tumor bed defined by postoperative computed tomography (post-CT) in prone position registered with or without preoperative magnetic resonance imaging (pre-MRI).

Methods

A total of 22 patients were included with early-stage breast invasive ductal cancer, who have undergone breast-conservative surgery and received the pre-MRI and post-CT in prone position. The MRI sequences (T1W, T2W, T2W-SPAIR, DWI, dyn-eTHRIVE, sdyn-eTHRIVE) were delineated and manually registered to CT, respectively. The clinical target volumes (CTVs) and planning target volumes (PTVs) were contoured on CT and different MRI sequences, respectively. Differences were measured in terms of consistence index (CI), dice coefficient (DC), geographical miss index (GMI), and normal tissue index (NTI).

Results

The differences of delineation volumes among CT and MRIs were significant, both in the CTVs (p = 0.035) and PTVs (p < 0.001). The values of CI and DC for sdyn-eTHRIVE registration to CT were the largest among all MRI sequences, but GMI and NTI were the smallest. No obvious linear correlation (p > 0.05) between the CI derived from the registration of CT and sdyn-eTHRIVE of CTV with the breast volume, the cavity visualization score (CVS) of CT, time interval from surgery to CT simulation, the maximum diameter of the intraoperative mass, and the number of titanium clips, respectively.

Conclusions

The CTVs and PTVs in MRI sequences were all smaller than those in CT. The pre-MRI, especially the sdyn-eTHRIVE, could be used to optimize the post-CT-based target delineation of breast cancer.

Key Points

• Registered pre-MRI to post-CT in order to improve the accuracy of target volume delineation of breast cancer.

• The CTVs and PTVs in MRI sequences were all smaller than those in CT.

• The sdyn-eTHRIVE of pre-MRIs may be a better choice to improve the delineation of CT-based CTV and PTV.

Electronic supplementary material

The online version of this article (10.1007/s00330-020-07085-0) contains supplementary material, which is available to authorized users.

Breast density, MR imaging biomarkers, and breast cancer risk

Mammographic breast density and various breast MRI features are imaging biomarkers that can predict a woman's future risk of breast cancer. While mammographic density (MD) has been established as an independent risk factor for the development of breast cancer, MD assessment methods need to be accurate and reproducible for widespread clinical use in stratifying patients based on their risk. In addition, a number of breast MRI biomarkers using contrast-enhanced and noncontrast-enhanced techniques are also being investigated as risk predictors. The validation and standardization of these breast MRI biomarkers will be necessary for population-based clinical implementation of patient risk stratification, as well. This review provides an update on MD assessment methods, breast MRI biomarkers, and their ability to predict breast cancer risk.

Predictive factors of major deviation (>20 mm) between lesion sizes measured by magnetic resonance imaging and histology for invasive lobular breast cancer

OBJECTIVE

To identify factors predictive of high discordance (>20 mm) between lesion sizes measured by magnetic resonance imaging (MRI) and histology for invasive lobular breast cancer.

MATERIALS AND METHODS

Data for all women with invasive lobular breast cancer (pure or associated with a component of invasive ductal carcinoma) between 1st January 2007 and 31st December 2016 were included in this study. Logistic regression analysis was performed to determine factors predictive of high discordance (underestimation/overestimation by >20 mm) between tumour sizes measured by MRI and histology for invasive lobular breast cancer.

RESULTS

For overestimation, significant factors on univariate analysis were: menopausal status [odds ratio (OR) 0.27, 95 % confidence interval (CI) 0.10-0.71]; p = 0.01], hormone receptor (HR) status (HR negative, OR 1.64, 95 % CI 0.27-9.89; HR positive, OR 0.64, 95 % CI 0.21-1.88; p = 0.09) and neoadjuvant chemotherapy (OR 10.33, 95 % CI 3.58-29.8; p < 0.001). On multivariate analysis, menopausal status and neoadjuvant chemotherapy were found to be independent predictive factors of overestimation. For underestimation, significant factors on univariate analysis were: histological size (OR 1.05, 95 % CI 1.02-1.08; p < 0.0001) and the presence of an in-situ component (OR 4.66, 95 % CI 1.01-21.5; p = 0.02). These two factors were independent predictive factors of underestimation.

CONCLUSION

Independent predictive factors of overestimation/underestimation (threshold 20 mm) of tumour sizes measured by MRI compared with histology for invasive lobular breast cancer were identified.

Comparison of mammography, digital breast tomosynthesis, automated breast ultrasound, magnetic resonance imaging in evaluation of residual tumor after neoadjuvant chemotherapy

BACKGROUND

To compare the accuracy of mammography (MG), digital breast tomosynthesis (DBT), automated breast ultrasound (ABUS) and magnetic resonance imaging (MRI) for the assessment of residual tumor extent in breast cancer after neoadjuvant chemotherapy (NAC).

METHODS

Fifty-one stage II-III breast cancer undergoing NAC were enrolled from March 2015 to December 2016. The longest diameter of residual tumor measured with MG, DBT, ABUS and MRI was compared with the pathologic tumor size. Statistical analysis was performed using intraclass correlation coefficients (ICC) and marginal homogeneity test. Receiver operating characteristics (ROC) analysis was used to evaluate the diagnostic performance for predicting pathologic complete response (pCR).

RESULTS

MRI size correlated well with pathology (ICC = 0.83), significantly better than MG, DBT and ABUS size (ICC = 0.56, ICC = 0.63 and ICC = 0.55, respectively). The discrepancy between MRI and pathology was statistical different from that of MG and ABUS (p = 0.0231 and 0.0039, respectively), but not different from that of DBT (p = 0.5727). For predicting pCR, MRI and DBT had a better performance compared to MG and US (area under the ROC curve: 0.92, 0.84, 0.72, 0.75, respectively; p = 0.3749 for DBT, p = 0.0972 for MG and p = 0.0596 for ABUS, when MRI being reference).

CONCLUSIONS

MRI and DBT allow more accurate assessment of tumor size compared to pathology compared with MG and ABUS. MRI and DBT outperform MG and ABUS in the prediction of pathologic complete response.

Breast Microcalcifications Studied with 3d Contrast-enhanced High-field Magnetic Resonance Imaging: More Accuracy in the Diagnosis of Breast Cancer

Aims

To evaluate the reliability of magnetic resonance imaging (MRI) performed with three-dimensional (3D) sequences in mammographically detected breast microcalcifications.

Methods

During an 8-month period, a group of 28 patients with mammographically detected microcalcifications suspicious for malignancy underwent MRI. Their ages ranged from 33 to 65 years. Examinations were performed with a 1.5 Tesla MR unit and a 3D T1 weighted sequence. Images were interpreted on the basis of morphologic parameters and dynamic behavior in the uptake of contrast medium (Gd-DTPA). Histologic findings were considered as the gold reference.

Results

Histologic analysis revealed invasive carcinoma in 7 patients, 3 of which were associated with foci of lobular carcinoma in situ. Intraductal carcinoma was diagnosed in 8 patients, 1 of which was associated with a tubular carcinoma. Benign lesions accounted for 13 patients. All the neoplastic conditions showed enhancement on MR images (sensitivity, 100%), whereas early and intense enhancement was noted in 5 of 13 benign lesions (specificity, 61%). The positive predictive value was 75% and negative predictive value, 100%.

Conclusions

Although an overlap in the enhancement behavior of malignant and some benign lesions is clearly evident, a careful interpretation of MR images is helpful in detecting and mainly ruling out breast cancer combined with mammographically suspicious microcalcifications.

Locally Advanced Breast Cancer Treated with Primary Chemotherapy: Comparison between Magnetic Resonance Imaging and Pathologic Evaluation of Residual Disease

Aims and Background

We evaluated the response of locally advanced breast cancer to induction chemotherapy using MRI techniques. The size and vitality of any residual pathologic tissue was quantified by means of morphologic and dynamic analysis. A curve derived from the dynamic parameters shows the uptake intensity with respect to the time elapsed since administration, which is related to vascularization and therefore indirectly reflects the angiogenesis of malignant tissue.

Methods and Study Design

A group of 30 patients were examined with MRI for staging purposes before undergoing treatment and subsequently to assess the response to treatment. Alterations in size and dynamic parameters were closely monitored.

Results

The overall accuracy was 90%, the sensitivity 96%, the specificity 75%, the positive predictive value 92.5% and the negative predictive value 66%. Interestingly, analysis of the dynamic curves made it possible to obtain additional information regarding the angiogenetic activity of the residual tumor.

Conclusions

Evaluation of the response to treatment by means of conventional imaging and clinical examination can be particularly difficult because of the fibrosis induced by cytotoxic drugs or the small volume of residual disease. The additional information supplied by MRI could therefore allow a more conservative surgical approach in selected cases of optimal response to treatment, as well as a much more accurate follow-up. Furthermore, the variation in dynamic parameters according to the vitality of residual disease could in the future become a useful tool for monitoring the effectiveness of anti-angiogenetic drugs.

Lobular Breast Cancer: How Useful is Breast Magnetic Resonance Imaging?

Rationale and objectives

To review magnetic resonance imaging (MRI) findings in lobular breast carcinoma, the in situ or infiltrating subtype, with special attention to the dynamic curves with the aim to evaluate possible differences with ductal carcinoma.

Methods

In 2 years, 27 patients with lobular and one with tubular carcinoma underwent MRI at the Istituto Nazionale Tumori of Milan.

Results

All lobular carcinomas demonstrated early or late enhancement (100% sensitivity), without significant differences in morphology compared with ductal carcinoma, but frequently with a different shape of the dynamic curves.

Conclusions

Due to its infiltrative growth associated to only limited connective tissue reaction, lobular carcinoma often encounters difficulties in mammographic diagnosis. In contrast, MRI can be very helpful in evaluating the true extension of the disease, especially when breast conservation is considered. Due to a more consistent fibrotic stroma, these lesions sometimes show a delayed enhancement, which suggests that more than one set of subtracted images should be evaluated during MRI analysis.

Apparent Diffusion Coefficient to Subdivide Breast Imaging Reporting and Data System Magnetic Resonance Imaging (BI-RADS-MRI) Category 4 Lesions

BACKGROUND This study aims to subdivide BI-RADS-MRI (Breast Imaging Reporting and Data System Magnetic Resonance Imaging) Category 4 lesions and to evaluate the role of Fischer's scoring system, apparent diffusion coefficient (ADC), and Fischer's + ADC in differential diagnosis of breast lesions. MATERIAL AND METHODS This study retrospectively analyzed the data of 143 patients (150 breast lesions), who were diagnosed by biopsy, and received dynamic contrast enhancement and diffusion-weighted imaging. The diagnostic efficacies of ADC, Fischer's scoring system, and the Fischer's + ADC were analyzed by the receiver operating characteristics curve. The area under the curve (AUC) was calculated. Fischer's scoring system and the Fischer's + ADC were used to subdivide BI-RADS Category 4 breast lesions. RESULTS ADC value was negatively correlated with the tumor grade. The AUC of Fischer's + ADC (0.949) was significantly higher than that of ADC (0.855) and Fischer's (0.912) (P=0.0008 and 0.001, respectively). Scored by Fischer's scoring system, Category 4 and 5 indicated a likely malignant threshold with sensitivity and specificity of 98.70% and 65.75%, respectively. Scored by the Fischer's + ADC method, Category 4B and 4C indicated a likely malignant threshold with sensitivity of 97.40% and specificity of 82.19%. Kappa values were 0.63 (ADC), 0.65 (Fischer's), and 0.80 (Fischer's + ADC), respectively. The positive predictive value of BI-RADS 4A, 4B, and 4C were 7.69%, 52.38% and 89.29%, respectively. CONCLUSIONS Fischer's scoring system combined with ADC could reasonably subdivide Category 4 breast lesions with high specificity and sensitivity.

Role of MR Imaging in Neoadjuvant Therapy Monitoring

Neoadjuvant chemotherapy (NAC) has become an important treatment approach for stage II/III breast cancers to downsize tumor and enable breast-conserving surgery for patients that may otherwise undergo mastectomy. MR imaging has the potential to identify early response or disease progression, enabling potential modification to NAC regimens. Detection of size and morphologic changes is better appreciated with MR imaging than other modalities and is different between molecular subtypes of breast cancer. The combination of DCE-MR imaging and DWI provides the highest sensitivity and specificity. Other new modalities such as FDG PET/MR imaging and molecular breast imaging are still undergoing research.

Apparent Diffusion Coefficient Value to Evaluate Tumor Response After Neoadjuvant Chemotherapy in Patients with Breast Cancer

RATIONALE AND OBJECTIVES

This study explored tumor behavior in patients with breast cancer during neoadjuvant chemotherapy (NAC) by sequential measurements of tumor apparent diffusion coefficient (ADC) after each chemotherapy cycle. The aim was to determine if the tumor ADC is useful to differentiate complete pathological response (cPR) from partial pathological response (pPR) during NAC.

MATERIALS AND METHODS

A total of 16 cases (in 14 patients) with diagnosis of breast cancer eligible to receive NAC were included. There were 70 magnetic resonance imaging examinations performed, 5 for each patient, during NAC cycles. Diffusion-weighted imaging was performed on a 1.5T system (b values of 0 and 700s/mm²). Four ADC ratios between the five MRI examinations were obtained to assess ADC changes during NAC. Absence of invasive breast cancer at surgical specimens (Miller-Payne 5) was considered as cPR and was used as reference for ADC cutoff ratios.

RESULTS

In this study, we were able to differentiate between cPR and pPR, after two cycles of NAC until the end of NAC before surgery (ADC ratios 2-4). The thresholds to differentiate between cPR and pPR of ADC ratios 2, 3, and 4, were 1.14 × 10^-3mm²/s, 1.08 × 10^-3mm²/s, and 1.25 × 10^-3mm²/s, respectively, and have a cross-validated sensitivity and specificity of 79.2%, 79.7% (ADC ratio 2); 100%, 66.7% (ADC ratio 3); and 100%, 83.8% (ADC ratio 4), respectively.

CONCLUSIONS

The ADC ratios were useful to differentiate cPR from pPR in breast cancer tumors after NAC. Thus, it may be useful in tailoring treatment in these patients.

Correlation between Magnetic Resonance Imaging and Histopathological Tumor Response after Neoadjuvant Chemotherapy in Breast Cancer

Aim

To evaluate the accuracy of magnetic resonance imaging in assessing tumor response following neoadjuvant chemotherapy in patients with locally advanced breast cancer.

Materials and Methods

Twenty-six patients entered a phase II study of neoadjuvant chemotherapy, undergoing bilateral breast magnetic resonance imaging before therapy and before surgery. Tumor response was classified using RECIST criteria, using tumor size at magnetic resonance imaging. The latter was then compared to residue found at histopathological examination.

Results

Magnetic resonance imaging showed 6 (23%) complete responses, 17 (65%) partial responses, 3 (11.5%) disease stabilizations and no disease progressions. Twenty-three tumors (88.5%) were considered responsive and 3 (11.5%) unresponsive. Pathological tumor response was: 6 complete responses (23%), 17 partial responses (65%), 2 stable disease (8%), 1 progression (4%). When results of the preoperative magnetic resonance imaging were compared to pathological tumor response, magnetic resonance imaging overestimated tumor size in 12 cases (46%) and underestimated it in 9 (35%). However, preoperative magnetic resonance imaging failed to detect invasive tumor in 2 false-negative cases (8%), 1 of which was multifocal. Mastectomy was performed in 12 cases: 1 case of disease progression even though the neoplasm appeared smaller at magnetic resonance imaging, 3 cases with stable disease, and 4 cases with T3 or T4 disease. The 9th patient was T2N2 with initial retroareolar disease and negative magnetic resonance imaging after chemotherapy. The 10th patient, affected by lobular cancer, was in partial remission but was T3N1. The 11th patient was 57 years old but was not interested in conservative surgery. The 12th patient requested bilateral prophylactic mastectomy due to her positive family history of breast cancer.

Conclusions

Magnetic resonance imaging of the breast allowed conservative surgery in 54% of the patients. This low value is primarily due to overestimation of tumor size, with a negative predictive value of 67% in our population. However, surgeons were able to choose conservative surgery with relative safety in cases of small residual disease.

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

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

Diffuse optical tomography for breast cancer imaging guided by computed tomography: A feasibility study

Diffuse optical tomography (DOT) has attracted attentions in the last two decades due to its intrinsic sensitivity in imaging chromophores of tissues such as hemoglobin, water, and lipid. However, DOT has not been clinically accepted yet due to its low spatial resolution caused by strong optical scattering in tissues. Structural guidance provided by an anatomical imaging modality enhances the DOT imaging substantially. Here, we propose a computed tomography (CT) guided multispectral DOT imaging system for breast cancer imaging. To validate its feasibility, we have built a prototype DOT imaging system which consists of a laser at the wavelength of 650 nm and an electron multiplying charge coupled device (EMCCD) camera. We have validated the CT guided DOT reconstruction algorithms with numerical simulations and phantom experiments, in which different imaging setup parameters, such as projection number of measurements and width of measurement patch, have been investigated. Our results indicate that an air-cooling EMCCD camera is good enough for the transmission mode DOT imaging. We have also found that measurements at six angular projections are sufficient for DOT to reconstruct the optical targets with 2 and 4 times absorption contrast when the CT guidance is applied. Finally, we have described our future research plan on integration of a multispectral DOT imaging system into a breast CT scanner.

Outcomes of Preoperative MRI-Guided Needle Localization of Nonpalpable Mammographically Occult Breast Lesions

OBJECTIVE

MRI-guided needle localization allows access to MRI-detected mammographically occult breast lesions that are not amenable to MRI-guided biopsy. The purpose of this study was to examine the safety and outcomes of MRI-guided needle localization.

MATERIALS AND METHODS

Ninety-nine consecutive breast lesions that underwent preoperative MRI-guided needle localization were identified. Clinical indications for breast MRI, reasons for performing MRI-guided needle localization, and surgical pathology results were recorded. Lesion characteristics, procedure time, and complications were assessed.

RESULTS

Of 99 lesions, 60 (60.6%) were in a location inaccessible for MRI biopsy, necessitating MRI-guided needle localization. Histologic evaluation revealed 38 (38.4%) carcinomas, 31 (31.3%) high-risk lesions, and 30 (30.3%) benign lesions. Carcinoma was more likely to be found in women with known cancer (31/61 [50.8%]; p = 0.003) than in women undergoing imaging for high-risk screening (2/18 [11.1%]) or problem solving (6/20 [30%]). Masses (p = 0.013) and foci (p < 0.001) were more likely to be malignant than were lesions with nonmass enhancement. Foci were significantly more often malignant compared with all other lesion types (9/10 [90%]; p < 0.001). The mean (± SD) procedure time was 32.9 ± 9.39 minutes. All lesions were occult on specimen radiographs. There were no procedure-related complications.

CONCLUSION

The positive predictive value of MRI-guided needle localization (38.4%) is comparable to that of mammography- and tomosynthesis-guided localizations and is highest in women with a known diagnosis of cancer. It is highly accurate in targeting small enhancing lesions, thereby improving surgical management. MRI-guided needle localization is a safe, accurate, and time-efficient procedure.

Changes in Glucose Metabolism and Blood Flow Following Chemotherapy for Breast Cancer

This article focuses on this application of positron emission tomography (PET) to breast cancer. The article first reviews the PET methodology used for breast cancer response assessment, with an emphasis on quantitative methods. This is followed by a review of results to date for neoadjuvant chemotherapy and therapy of metastatic breast cancer. Preliminary studies with tracers other than (18)F-fluordeoxyglucose are then reviewed. The article ends with a summary and a discussion of future directions.

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

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

Effective factors to raise diagnostic performance of breast MRI for diagnosing pathologic complete response in breast cancer patients after neoadjuvant chemotherapy

BACKGROUND

Although MRI is a highly effective tool in evaluating residual disease after neoadjuvant chemotherapy (NAC), there are many reports of discordance between the response of MRI and pathology. To increase MR accuracy, additional methods, which reflect post-NAC changes, should be considered in diagnosis.

PURPOSE

To evaluate effective methods that raise the diagnostic performance of MRI for predicting pathologic complete response (pCR) in breast cancer after neoadjuvant chemotherapy (NAC).

MATERIAL AND METHODS

For 98 invasive breast carcinoma patients, chemotherapeutic response to MRI was evaluated for the following parameters: tumor size, tumor distribution pattern, kinetic curve analysis, and background parenchymal enhancement pattern (BPE). BPE was categorized as "minimal", "mild", "moderate", or "marked", according to the ACR BI-RADS criteria.

RESULTS

After NAC, the mean size of tumors decreased by 40% in non-pCR and by 59% in pCR groups, respectively. The sensitivity, specificity, false positive rate and false negative rate of MRI were 96% (78/81), 53% (9/17), 47% (8/17), and 4% (3/81), respectively. At pre-NAC MRI, the most common kinetic curve was delayed washout pattern (68%, 67/98); however, at post-NAC MRI the persistent pattern (55%, 47/86). Grouped lesion was the most common tumor distribution pattern on pre-NAC MRI (28%, 27/98), while on post-NAC solitary mass (40%, 34/86). The most common BPE at pre- and post-NAC MRI was mild and minimal enhancement, respectively.

CONCLUSION

To improve the diagnostic accuracy of MRI, we should consider additional factors including: tumor distribution pattern, BPE, kinetic curve analysis, and tumor size.

The evolution of breast imaging: past to present

The practice of breast imaging has transitioned through a wide variety of technologic advances from the early days of direct-exposure film mammography to xeromammography to screen-film mammography to the current era of full-field digital mammography and digital breast tomosynthesis. Along with these technologic advances, organized screening, federal regulations based on the Mammography Quality Standards Act, and the development of the American College of Radiology Breast Imaging Reporting and Data System have helped to shape the specialty of breast imaging. With the development of breast ultrasonography and breast magnetic resonance imaging, both complementary to mammography, additional algorithms for diagnostic workup and screening high-risk subgroups of women have emerged. A substantial part of breast imaging practice these days also involves breast interventional procedures-both percutaneous biopsy to obtain tissue diagnosis and localization procedures to guide surgical excision. This article reviews the evolution of breast imaging starting from a historical perspective and progressing to the present day.

Analyzing Spatial Heterogeneity in DCE- and DW-MRI Parametric Maps to Optimize Prediction of Pathologic Response to Neoadjuvant Chemotherapy in Breast Cancer

The purpose of this study is to investigate the ability of multivariate analysis of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion-weighted MRI (DW-MRI) parametric maps, obtained early in the course of therapy, to predict which patients will achieve pathologic complete response (pCR) at the time of surgery. Thirty-three patients underwent DCE-MRI (to estimate K (trans), v e, k ep, and v p) and DW-MRI [to estimate the apparent diffusion coefficient (ADC)] at baseline (t 1) and after the first cycle of neoadjuvant chemotherapy (t 2). Four analyses were performed and evaluated using receiver-operating characteristic (ROC) analysis to test their ability to predict pCR. First, a region of interest (ROI) level analysis input the mean K (trans), v e, k ep, v p, and ADC into the logistic model. Second, a voxel-based analysis was performed in which a longitudinal registration algorithm aligned serial parameters to a common space for each patient. The voxels with an increase in k ep, K (trans), and v p or a decrease in ADC or v e were then detected and input into the regression model. In the third analysis, both the ROI and voxel level data were included in the regression model. In the fourth analysis, the ROI and voxel level data were combined with selected clinical data in the regression model. The overfitting-corrected area under the ROC curve (AUC) with 95% confidence intervals (CIs) was then calculated to evaluate the performance of the four analyses. The combination of k ep, ADC ROI, and voxel level data achieved the best AUC (95% CI) of 0.87 (0.77-0.98).

DCE-MRI analysis methods for predicting the response of breast cancer to neoadjuvant chemotherapy: pilot study findings

PURPOSE

The purpose of this pilot study is to determine (1) if early changes in both semiquantitative and quantitative DCE-MRI parameters, observed after the first cycle of neoadjuvant chemotherapy in breast cancer patients, show significant difference between responders and nonresponders and (2) if these parameters can be used as a prognostic indicator of the eventual response.

METHODS

Twenty-eight patients were examined using DCE-MRI pre-, post-one cycle, and just prior to surgery. The semiquantitative parameters included longest dimension, tumor volume, initial area under the curve, and signal enhancement ratio related parameters, while quantitative parameters included K(trans), v(e), k(ep), v(p), and τ(i) estimated using the standard Tofts-Kety, extended Tofts-Kety, and fast exchange regime models.

RESULTS

Our preliminary results indicated that the signal enhancement ratio washout volume and k(ep) were significantly different between pathologic complete responders from nonresponders (P < 0.05) after a single cycle of chemotherapy. Receiver operator characteristic analysis showed that the AUC of the signal enhancement ratio washout volume was 0.75, and the AUCs of k(ep) estimated by three models were 0.78, 0.76, and 0.73, respectively.

CONCLUSION

In summary, the signal enhancement ratio washout volume and k(ep) appear to predict breast cancer response after one cycle of neoadjuvant chemotherapy. This observation should be confirmed with additional prospective studies.

Current and emerging quantitative magnetic resonance imaging methods for assessing and predicting the response of breast cancer to neoadjuvant therapy

Reliable early assessment of breast cancer response to neoadjuvant therapy (NAT) would provide considerable benefit to patient care and ongoing research efforts, and demand for accurate and noninvasive early-response biomarkers is likely to increase. Response assessment techniques derived from quantitative magnetic resonance imaging (MRI) hold great potential for integration into treatment algorithms and clinical trials. Quantitative MRI techniques already available for assessing breast cancer response to neoadjuvant therapy include lesion size measurement, dynamic contrast-enhanced MRI, diffusion-weighted MRI, and proton magnetic resonance spectroscopy. Emerging yet promising techniques include magnetization transfer MRI, chemical exchange saturation transfer MRI, magnetic resonance elastography, and hyperpolarized MR. Translating and incorporating these techniques into the clinical setting will require close attention to statistical validation methods, standardization and reproducibility of technique, and scanning protocol design.

Computer-aided evaluation of breast MRI for the residual tumor extent and response monitoring in breast cancer patients receiving neoadjuvant chemotherapy

Objective

To evaluate the accuracy of a computer-aided evaluation program (CAE) of breast MRI for the assessment of residual tumor extent and response monitoring in breast cancer patients receiving neoadjuvant chemotherapy.

Materials and Methods

Fifty-seven patients with breast cancers who underwent neoadjuvant chemotherapy before surgery and dynamic contrast enhanced MRI before and after chemotherapy were included as part of this study. For the assessment of residual tumor extent after completion of chemotherapy, the mean tumor diameters measured by radiologists and CAE were compared to those on histopathology using a paired student t-test. Moreover, the agreement between unidimensional (1D) measurement by radiologist and histopathological size or 1D measurement by CAE and histopathological size was assessed using the Bland-Altman method. For chemotherapy monitoring, we evaluated tumor response through the change in the 1D diameter by a radiologist and CAE and three-dimensional (3D) volumetric change by CAE based on Response Evaluation Criteria in Solid Tumors (RECIST). Agreement between the 1D response by the radiologist versus the 1D response by CAE as well as by the 3D response by CAE were evaluated using weighted kappa (k) statistics.

Results

For the assessment of residual tumor extent after chemotherapy, the mean tumor diameter measured by radiologists (2.0 ± 1.7 cm) was significantly smaller than the mean histological diameter (2.6 ± 2.3 cm) (p = 0.01), whereas, no significant difference was found between the CAE measurements (mean = 2.2 ± 2.0 cm) and histological diameter (p = 0.19). The mean difference between the 1D measurement by the radiologist and histopathology was 0.6 cm (95% confidence interval: -3.0, 4.3), whereas the difference between CAE and histopathology was 0.4 cm (95% confidence interval: -3.9, 4.7). For the monitoring of response to chemotherapy, the 1D measurement by the radiologist and CAE showed a fair agreement (k = 0.358), while the 1D measurement by the radiologist and 3D measurement by CAE showed poor agreement (k = 0.106).

Conclusion

CAE for breast MRI is sufficiently accurate for the assessment of residual tumor extent in breast cancer patients receiving neoadjuvant chemotherapy. However, for the assessment of response to chemotherapy, the assessment by the radiologist and CAE showed a fair to poor agreement.

MR and US imaging for breast cancer patients who underwent conservation surgery after neoadjuvant chemotherapy: comparison of triple negative breast cancer and other intrinsic subtypes

BACKGROUND

Neoadjuvant chemotherapy (NAC) is commonly utilized to treat operable breast cancer. The purpose of this study was to review the findings of ultrasonography (US) and magnetic resonance (MR) imaging in patients treated with breast conservation surgery (BCS) after NAC with a focus on intrinsic subtypes.

METHODS

Eighty-six patients underwent BCS after NAC. The tumors were classified into four subgroups by receptor status. US and MR were performed before and after NAC. The tumor diameters in US and MR after NAC were examined for correlations with pathological tumor distances in the specimens from BCS after NAC.

RESULTS

The correlation coefficient (r) of US to pathological tumor size was 0.3 in all tumors, 0.6 in HER2-type tumors, and 0.7 in triple negative breast cancers (TNBC). The correlation coefficient of tumor size in MR to pathological tumor size was 0.9 in TNBC, and other correlations were not statistically significant.

CONCLUSIONS

The correlation between tumor size in MR and pathological tumor size in triple negative breast cancers corresponded best. This information is one of the clues to selecting patients for BCS after NAC.

Comparison of mammography, sonography, MRI and clinical examination in patients with locally advanced or inflammatory breast cancer who underwent neoadjuvant chemotherapy

OBJECTIVES

The purpose of this study was to determine the relative accuracies of mammography, sonography, MRI and clinical examination in predicting residual tumour size and pathological response after neoadjuvant chemotherapy for locally advanced or inflammatory breast cancer. Each prediction method was compared with the gold standard of surgical pathology.

METHODS

43 patients (age range, 25-62 years; mean age, 42.7 years) with locally advanced or inflammatory breast cancer who had been treated by neoadjuvant chemotherapy were enrolled prospectively. We compared the predicted residual tumour size and the predicted response on imaging and clinical examination with residual tumour size and response on pathology. Statistical analysis was performed using weighted kappa statistics and intraclass correlation coefficients (ICC).

RESULTS

The ICC values between predicted tumour size and pathologically determined tumour size were 0.65 for clinical examination, 0.69 for mammography, 0.78 for sonography and 0.97 for MRI. Agreement between the response predictions at mid-treatment and the responses measured by pathology had kappa values of 0.28 for clinical examination, 0.32 for mammography, 0.46 for sonography and 0.68 for MRI. Agreement between the final response predictions and the responses measured by pathology had kappa values of 0.43 for clinical examination, 0.44 for mammography, 0.50 for sonography and 0.82 for MRI.

CONCLUSION

Predictions of response and residual tumour size made on MRI were better correlated with the assessments of response and residual tumour size made upon pathology than were predictions made on the basis of clinical examination, mammography or sonography. Thus, the evaluation of predicted response using MRI could provide a relatively sensitive early assessment of chemotherapy efficacy.

Detecting treatment response in a model of human breast adenocarcinoma using hyperpolarised [1-13C]pyruvate and [1,4-13C2]fumarate

BACKGROUND

The recent introduction of a dynamic nuclear polarisation technique has permitted noninvasive imaging of tumour cell metabolism in vivo following intravenous administration of (13)C-labelled cell substrates.

METHODS

Changes in hyperpolarised [1-(13)C]pyruvate and [1,4-(13)C(2)]fumarate metabolism were evaluated in both MDA-MB-231 cells and in implanted MDA-MB-231 tumours following doxorubicin treatment.

RESULTS

Treatment of MDA-MB-231 cells resulted in the induction of apoptosis, which was accompanied by a decrease in hyperpolarised (13)C label flux between [1-(13)C]pyruvate and lactate, which was correlated with a decrease in the cellular NAD(H) coenzyme pool. There was also an increase in the rate of fumarate conversion to malate, which accompanied the onset of cellular necrosis. In vivo, the decrease in (13)C label exchange between pyruvate and lactate and the increased flux between fumarate and malate, following drug treatment, were shown to occur in the absence of any detectable change in tumour size.

CONCLUSION

We show here that the early responses of a human breast adenocarcinoma tumour model to drug treatment can be followed by administration of both hyperpolarised [1-(13)C]pyruvate and [1,4-(13)C(2)]fumarate. These techniques could be used, therefore, in the clinic to detect the early responses of breast tumours to treatment.

Role of breast MR imaging in neoadjuvant chemotherapy

Neoadjuvant chemotherapy is now widely used in the management of locally advanced breast cancer (LABC). Early initiation of systemic therapy can improve overall and disease-free survival for patients with LABC or inflammatory cancer. MR imaging with intravenous contrast and advanced MR imaging techniques provide new opportunities for assessing tumor morphologic changes, tumor vascularity, tumor cellularity, and tumor metabolic features. MR imaging is more reliable than the conventional methods in the assessment of tumor size and vascularity changes during and after chemotherapy. The addition of advanced imaging techniques to further characterize tumor cellularity and metabolic features appears promising. However, there is still no consensus on the role of MR imaging for assessing response to neoadjuvant chemotherapy or on a standardized MR imaging examination in patients receiving neoadjuvant chemotherapy.

Color Doppler ultrasonography for treatment response prediction and evaluation in breast cancer

Primary systemic therapy is a well-established modality of treatment in locally advanced breast cancer. Assessment of tumor response to chemotherapy not only helps in assessing the efficacy of the regimen used but also predicts the overall outcome of the patient. The tumor vascularity is a surrogate marker of tumor burden and this can be readily assessed by color Doppler ultrasound using various indices (resistivity index, pulsatility index and maximum flow velocity). The pre- and post-chemotherapy indices can be compared with in order assess the response to chemotherapy. Among various imaging modalities, MRI and PET have the highest sensitivity in detecting the tumor response, but they are not cost effective. Color Doppler ultrasound is a promising alternative for tumor response assessment owing to its availability, reproducibility and cost–effectiveness.

Molecular and Functional Imaging of Breast Cancer

Background

Significant efforts have been directed toward developing and enhancing imaging methods for the early detection, diagnosis, and characterization of small breast tumors. Molecular and functional imaging sets the stage for enhancement of current methodology.

Methods

Current imaging modalities are described based on the molecular characteristics of normal and malignant tissue. New molecular imaging methods that have the potential for clinical use are also discussed.

Results:

Dynamic contrast-enhanced magnetic resonance imaging is more sensitive than mammography in BRCA1 carriers. It is used in screening and in the early evaluation of neoadjuvant therapy. Positron emission mammography is 91% sensitive and 93% specific in detecting primary breast cancers. Sentinel node scintigraphy is a key component of axillary lymph node evaluation. Other imaging modalities being studied include Tc99m sestamibi, radiolabeled thymidine or uridine, estrogen receptor imaging, magnetic resonance spectroscopy, and diffusion magnetic resonance imaging.

Conclusions

Molecular and functional imaging of the breast will likely alter clinical practice in diagnosing and staging primary breast cancer and assessing response to therapy since it will provide earlier information regarding the underlying biology of individual breast cancers, tumor stage, potential treatment strategies, and biomarkers for early evaluation of treatment effects.

Diffusion-weighted magnetic resonance imaging for assessment after neoadjuvant chemotherapy in breast cancer, based on morphological concepts

The study aimed to evaluate the utility of diffusion-weighted imaging (DWI) and to assess the response of breast cancer patients to neoadjuvant chemotherapy (NAC), based on morphological concepts. This retrospective study included 35 breast cancer patients (36 lesions) who had conventional magnetic resonance imaging (MRI), with DWI acquired before and after NAC. The morphological pattern of delayed enhancement on MRI before NAC was classified into two types: focal mass (FM), and multiple masses and/or non-mass like (MM/NM), based on Breast Imaging Reporting and Data System (BI-RADS). Of the 36 tumors, 26 were classified as FM and 10 as MM/NM. Tumors were clearly visualized on the initial DWI although one case of suspected MM/NM was not observed on DWI following NAC. A correlation was found between changes in the apparent diffusion coefficient and response rates to NAC in FM tumors (r=0.608, p<0.001), but not in MM/NM tumors (r=0.141, p=0.717). There was agreement between MRI findings after NAC and pathological findings in 30 of the 36 tumors (83.3%). Thus, we concluded that DWI is potentially useful in assessing the response to NAC for breast cancer for tumors diagnosed as FM on the initial conventional MRI.

PET, PET/CT, and PET/MR Imaging Assessment of Breast Cancer

This review focuses mainly on clinical applications of PET/CT in patients with breast cancer. It discusses the role of 2-[18F]-fluoro-2-deoxy-D-glucose (FDG) PET/CT (and FDG PET) in the diagnosis and initial staging of breast cancer, in monitoring the response of disease to chemotherapy, and in identifying metastatic and recurrent disease. In addition, it discusses the role of MR imaging and potential future hybrid modalities such as PET/MR imaging.

Breast MRI: State of the Art

Magnetic resonance imaging (MRI) of the breast has emerged as a useful adjunct in evaluation of breast disease. For the past 25 years its use has been explored extensively in the literature and specific clinical indications have been developed. This review will address the current state of the art of breast MRI, including image acquisition, interpretation, limitations, and current applications. We also will discuss briefly emerging techniques that may further advance the practice of breast MRI evaluation.

Breast cancer screening in women at high risk using MRI

A series of prospective comparative studies have demonstrated that MRI has approximately twice the sensitivity of X-ray mammography for screening women at high familial risk of breast cancer. In these studies, lesions have often been detected at an early stage, with disease being small and predominantly node negative. The diagnostic features in relation to risk and the biological behaviour of disease with risk category and age are being evaluated. The results of these studies have resulted in revised recommendations for screening for women at high risk of breast cancer. In this article, the results of the UK Magnetic Resonance Imaging in Breast Cancer Screening (MARIBS) study of MRI screening are described, and compared with results from other studies. Risk factors identifying women who would benefit from MRI screening are discussed, MRI measurement methods are described, and the results of studies evaluating MRI and mammographic lesions in different risk groups are reviewed. Recommendations for screening women at high risk of breast cancer published by the American Cancer Society and from the National Institute for Health and Clinical Excellence (NICE) in the UK are summarised.

Dynamic contrast-enhanced MRI for prediction of breast cancer response to neoadjuvant chemotherapy: initial results

OBJECTIVE

The aim of this study was to establish changes in contrast-enhanced MRI of breast cancer during neoadjuvant chemotherapy that are indicative of pathology outcome.

MATERIALS AND METHODS

In 54 patients with breast cancer, dynamic contrast-enhanced MRI was performed before chemotherapy and after two chemotherapy cycles. Imaging was correlated with final histopathology. Multivariate analysis with cross-validation was performed on MRI features describing kinetics and morphology of contrast uptake in the early and late phases of enhancement. Receiver operating characteristic (ROC) analysis was used to develop a guideline that switches patients at high risk for incomplete remission to a different chemotherapy regimen while maintaining first-line therapy in 95% of patients who are not at risk (i.e., high specificity).

RESULTS

Change in largest diameter of late enhancement during chemotherapy was the single most predictive MRI characteristic for tumor response in multivariate analysis (A(z) [area under the ROC curve] = 0.73, p < 0.00001). Insufficient (< 25%) decrease in largest diameter of late enhancement during chemotherapy was most indicative of residual tumor at final pathology. Using this criterion, the fraction of unfavorable responders indicated by MRI was 41% (22/54). Approximately half (44%, 14/32) of the patients who showed favorable response at MRI achieved complete remission at pathology. Conversely, 95% (21/22) of patients who showed unfavorable response at MRI had residual tumor at pathology.

CONCLUSION

Reduction of less than 25% in largest diameter of late enhancement during neoadjuvant chemotherapy shows the potential to predict residual tumor after therapy with high specificity.

Early changes in functional dynamic magnetic resonance imaging predict for pathologic response to neoadjuvant chemotherapy in primary breast cancer

PURPOSE

Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) allows noninvasive, in vivo measurements of tissue microvessel perfusion and permeability. We examined whether DCE-MRI done after two cycles of neoadjuvant chemotherapy could predict final clinical and pathologic response in primary breast cancers.

EXPERIMENTAL DESIGN

Thirty-seven patients with primary breast cancer, due to receive six cycles of neoadjuvant 5-fluorouracil, epirubicin and cyclophosphamide chemotherapy, were examined using DCE-MRI before neoadjuvant chemotherapy and after two cycles of treatment. Changes in DCE-MRI kinetic parameters (K(trans), k(ep), v(e), MaxGd, rBV, rBF, MTT) were correlated with the final clinical and pathologic response to neoadjuvant chemotherapy. Test-retest variability was used to determine individual patient response.

RESULTS

Twenty-eight patients were evaluable for response (19 clinical responders and 9 nonresponders; 11 pathologic responders and 17 nonresponders). Changes in the DCE-MRI kinetic parameters K(trans), k(ep), MaxGd, rBV, and rBF were significantly correlated with both final clinical and pathologic response (P < 0.01). Change in K(trans) was the best predictor of pathologic nonresponse (area under the receiver operating characteristic curve, 0.93; sensitivity, 94%; specificity, 82%), correctly identifying 94% of nonresponders and 73% of responders. Change in MRI-derived tumor size did not predict for pathologic response.

CONCLUSION

Changes in breast tumor microvessel functionality as depicted by DCE-MRI early on after starting anthracycline-based neoadjuvant chemotherapy can predict final clinical and pathologic response. The ability to identify nonresponders early may allow the selection of patients who may benefit from a therapy change.

Gadobenate dimeglumine as a contrast agent for dynamic breast magnetic resonance imaging: effect of higher initial enhancement thresholds on diagnostic performance

RATIONALE AND OBJECTIVE

Gadobenate dimeglumine (Gd-BOPTA), a high-relaxivity contrast agent, has been recently proposed for dynamic MR imaging of the breast. The objective of this study was to optimize the diagnostic performance of Gd-BOPTA-enhanced dynamic breast MR imaging by using adjusted initial enhancement thresholds.

METHODS

Thirty-four patients with 36 breast lesions (malignant/benign = 28/8) underwent dynamic breast MRI with 0.1 mmol/kg Gd-BOPTA and 120-second time resolution. A score system based on shape (round/oval/lobular = 0; linear/dendritic/stellate = 1), margins (defined = 0; undefined = 1), pattern (homogeneous = 0; inhomogeneous = 1; rim = 2), kinetics (continuous = 0; plateau = 1; washout = 2), and initial enhancement was used. Initial enhancement was determined with standard (<50% = 0; 50%-100% = 1; >100% = 2) and adjusted (<100% = 0; 100%-240% = 1; >240% = 2) thresholds. Scores of 0 to 3 indicated benign lesions and scores of 4 to 8 malignant lesions. Diagnostic performance was assessed in terms of sensitivity, specificity, positive and negative predictive values, and overall accuracy.

RESULTS

The initial enhancement was >100% for 26 malignant and 7 benign lesions and >240% for 16 and 1 lesions, respectively. The overall score was 5.89 +/- 1.34 with standard thresholds and 5.50 +/- 1.53 with adjusted thresholds (P = 0.003) for cancers, 4.00 +/- 1.93 and 3.25 +/- 1.75 (P = 0.028) for benign lesions, respectively. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy was 96%, 13%, 79%, 50%, and 78%, respectively, with standard thresholds and 96%, 75%, 93%, 86%, and 92%, respectively, with adjusted thresholds. A ductal carcinoma in situ was false negative whereas a fat necrosis and a papilloma were false positive with both thresholds. Three fibroadenomas, 1 adenosis, and 1 fibrosis were false positive with standard thresholds but true negatives with adjusted thresholds.

CONCLUSIONS

Lesion characterization with Gd-BOPTA requires higher thresholds for initial enhancement than those used with conventional Gd-chelates, leading to improved specificity, predictive values, and accuracy.

Tumor metabolism and blood flow changes by positron emission tomography: relation to survival in patients treated with neoadjuvant chemotherapy for locally advanced breast cancer

PURPOSE

Patients with locally advanced breast carcinoma (LABC) receive preoperative chemotherapy to provide early systemic treatment and assess in vivo tumor response. Serial positron emission tomography (PET) has been shown to predict pathologic response in this setting. We evaluated serial quantitative PET tumor blood flow (BF) and metabolism as in vivo measurements to predict patient outcome.

PATIENTS AND METHODS

Fifty-three women with primary LABC underwent dynamic [(18)F]fluorodeoxyglucose (FDG) and [(15)O]water PET scans before and at midpoint of neoadjuvant chemotherapy. The FDG metabolic rate (MRFDG) and transport (FDG K(1)) parameters were calculated; BF was estimated from the [(15)O]water study. Associations between BF, MRFDG, FDG K(1), and standardized uptake value and disease-free survival (DFS) and overall survival (OS) were evaluated using the Cox proportional hazards model.

RESULTS

Patients with persistent or elevated BF and FDG K(1) from baseline to midtherapy had higher recurrence and mortality risks than patients with reductions. In multivariable analyses, BF and FDG K(1) changes remained independent prognosticators of DFS and OS. For example, in the association between BF and mortality, a patient with a 5% increase in tumor BF had a 67% higher mortality risk compared with a patient with a 5% decrease in tumor BF (hazard ratio = 1.67; 95% CI, 1.24 to 2.24; P < .001).

CONCLUSION

LABC patients with limited or no decline in BF and FDG K(1) experienced higher recurrence and mortality risks that were greater than the effects of clinical tumor characteristics. Tumor perfusion changes over the course of neoadjuvant chemotherapy measured directly by [(15)O]water or indirectly by dynamic FDG predict DFS and OS.

Prognostic value of pre-treatment DCE-MRI parameters in predicting disease free and overall survival for breast cancer patients undergoing neoadjuvant chemotherapy

The purpose of this study was to investigate whether dynamic contrast enhanced MRI (DCE-MRI) data, both pharmacokinetic and empirical, can predict, prior to neoadjuvant chemotherapy, which patients are likely to have a shorter disease free survival (DFS) and overall survival (OS) interval following surgery. Traditional prognostic parameters were also included in the survival analysis. Consequently, a comparison of the prognostic value could be made between all the parameters studied. MR examinations were conducted on a 1.5 T system in 68 patients prior to the initiation of neoadjuvant chemotherapy. DCE-MRI consisted of a fast spoiled gradient echo sequence acquired over 35 phases with a mean temporal resolution of 11.3s. Both pharmacokinetic and empirical parameters were derived from the DCE-MRI data. Kaplan-Meier survival plots were generated for each parameter and group comparisons were made utilising logrank tests. The results from the 54 patients entered into the univariate survival analysis demonstrated that traditional prognostic parameters (tumour grade, hormonal status and size), empirical parameters (maximum enhancement index, enhancement index at 30s, area under the curve and initial slope) and adjuvant therapies demonstrated significant differences in survival intervals. Further multivariate Cox regression survival analysis revealed that empirical enhancement parameters contributed the greatest prediction of both DFS and OS in the resulting models. In conclusion, this study has demonstrated that in patients who exhibit high levels of perfusion and vessel permeability pre-treatment, evidenced by elevated empirical DCE-MRI parameters, a significantly lower disease free survival and overall survival can be expected.