Magnetic Resonance Imaging in Comparison to Clinical Palpation in Assessing the Response of Breast Cancer to Epirubicin Primary Chemotherapy

Precise tumor delineation in clinical tissues using a novel acidic tumor microenvironment activatable near-infrared fluorescent contrast agent

Tumor selective near-infrared (NIR) fluorescent contrast agents has the potential to greatly enhance the efficiency and precision of tumor surgery by enabling real-time tumor margin identification for tumor resection guided by imaging. However, the development of these agents is still challenging. In this study, based on the acidic tumor microenvironment (TME), we designed and synthesized a novel pH-sensitive NIR fluorescent contrast agent OBD from β-carboline. The fluorescence quantum yield of OBD exhibited a notable increase at pH 3.6, approximately 12-fold higher compared to its value at pH 7.4. After cellular uptake, OBD lighted up the cancer cells with high specificity and accumulated in the mitochondria. Spraying OBD emitted selective fluorescence in xenograft tumor tissues with tumor-to-normal tissue ratios (TNR) as high as 11.18, implying successful image-guided surgery. Furthermore, OBD was also shown to track metastasis in spray mode. After simple topical spray, OBD rapidly and precisely visualized the tumor margins of clinical colon and liver tissues with TNR over 4.2. Therefore, the small-molecule fluorescent contrast agent OBD has promising clinical applications in tumor identification during surgery.

Imaging findings for response evaluation of ductal carcinoma in situ in breast cancer patients treated with neoadjuvant systemic therapy: a systematic review and meta-analysis

OBJECTIVES

In approximately 45% of invasive breast cancer (IBC) patients treated with neoadjuvant systemic therapy (NST), ductal carcinoma in situ (DCIS) is present. Recent studies suggest response of DCIS to NST. The aim of this systematic review and meta-analysis was to summarise and examine the current literature on imaging findings for different imaging modalities evaluating DCIS response to NST. More specifically, imaging findings of DCIS pre- and post-NST, and the effect of different pathological complete response (pCR) definitions, will be evaluated on mammography, breast MRI, and contrast-enhanced mammography (CEM).

METHODS

PubMed and Embase databases were searched for studies investigating NST response of IBC, including information on DCIS. Imaging findings and response evaluation of DCIS were assessed for mammography, breast MRI, and CEM. A meta-analysis was conducted per imaging modality to calculate pooled sensitivity and specificity for detecting residual disease between pCR definition no residual invasive disease (ypT0/is) and no residual invasive or in situ disease (ypT0).

RESULTS

Thirty-one studies were included. Calcifications on mammography are related to DCIS, but can persist despite complete response of DCIS. In 20 breast MRI studies, an average of 57% of residual DCIS showed enhancement. A meta-analysis of 17 breast MRI studies confirmed higher pooled sensitivity (0.86 versus 0.82) and lower pooled specificity (0.61 versus 0.68) for detection of residual disease when DCIS is considered pCR (ypT0/is). Three CEM studies suggest the potential benefit of simultaneous evaluation of calcifications and enhancement.

CONCLUSIONS AND CLINICAL RELEVANCE

Calcifications on mammography can remain despite complete response of DCIS, and residual DCIS does not always show enhancement on breast MRI and CEM. Moreover, pCR definition effects diagnostic performance of breast MRI. Given the lack of evidence on imaging findings of response of the DCIS component to NST, further research is demanded.

KEY POINTS

• Ductal carcinoma in situ has shown to be responsive to neoadjuvant systemic therapy, but imaging studies mainly focus on response of the invasive tumour. • The 31 included studies demonstrate that after neoadjuvant systemic therapy, calcifications on mammography can remain despite complete response of DCIS and residual DCIS does not always show enhancement on MRI and contrast-enhanced mammography. • The definition of pCR has impact on the diagnostic performance of MRI in detecting residual disease, and when DCIS is considered pCR, pooled sensitivity was slightly higher and pooled specificity slightly lower.

Accuracy of Posttreatment Imaging for Evaluation of Residual in Breast Disease After Neoadjuvant Endocrine Therapy

BACKGROUND

Neoadjuvant endocrine therapy (NET) can help downstage certain breast cancers prior to surgical resection. This study measured the accuracy of conventional mammography (MMG), ultrasound (US), magnetic resonance imaging (MRI), and contrast-enhanced mammography (CEM) for assessing breast tumor size in response to NET.

PATIENTS AND METHODS

Patients who underwent surgery after NET from 2013 to 2021 were identified. The maximal dimension of residual tumor on imaging was compared with the maximal dimension on final pathology. Lin's concordance correlation coefficient (r_c) and Spearman's rank correlation coefficient (r) were used to assess agreement.

RESULTS

In total, 119 patients with invasive breast cancer underwent NET, posttreatment imaging, and surgery. Tumor size reported on posttreatment CEM correlated with size on final pathology to within 1 cm in n = 42 (58%) of patients, equivalent to the accuracy of MRI (n = 35, 58%). Size was accurately predicted by US in 54% and in 48% of MMG. Posttreatment imaging tumor size was moderately correlated with final tumor size on pathology CEM (r = 0.49; r_c = 0.38), MRI (r = 0.52; r_c = 0.45), and US (r = 0.41; r_c = 0.28). MMG was weakly correlated (r = 0.21; r_c = 0.16). Similar findings were shown in subgroup analysis; in those who received all four post-NET imaging, CEM and MRI again performed comparably, with r = 0.36 and 0.41, respectively, US (r = 0.43) and MMG (r = 0.28).

CONCLUSIONS

Compared with mammography and US, CEM and MRI had higher accuracy in estimating final tumor size for breast cancers treated with NET. Contrast-enhanced imaging is a helpful adjunct when response to preoperative therapy will impact clinical management.

Feasibility of quantitative and volumetric enhancement measurement to assess tumor response in patients with breast cancer after early neoadjuvant chemotherapy

Objective

To evaluate the feasibility of quantitative enhancing lesion volume (ELV) for evaluating the responsiveness of breast cancer patients to early neoadjuvant chemotherapy (NAC) using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI).

Methods

Seventy-five women with breast cancer underwent DCE-MRI before and after NAC. Lesions were assessed by ELV, response evaluation criteria in solid tumors 1.1 (RECIST 1.1), and total lesion volume (TLV). The diagnostic and pathological predictive performances of the methods were compared and color maps were compared with pathological results.

Results

ELV identified 29%, 67%, and 4% of cases with partial response, stable disease, and progressive disease, respectively. There was no significant difference in evaluation performances among the methods. The sensitivity, specificity, positive predictive value, negative predictive value (NPV), and accuracy of ELV for predicting pathologic response were 72%, 92%, 81.8%, 86.8%, and 85.3%, respectively, with the highest sensitivity, NPV, and accuracy of the three methods. The area under the receiver operating characteristic curve was also highest for ELV. Pre- and post-NAC color maps reflecting tumor activity were consistent with pathological necrosis.

Conclusions

ELV may help evaluate the responsiveness of breast cancer patients to NAC, and may provide a good tumor-response indicator through the ability to indicate tumor viability.

Accuracy of breast MRI in patients receiving neoadjuvant endocrine therapy: comprehensive imaging analysis and correlation with clinical and pathological assessments

Purpose

To assess the accuracy of magnetic resonance imaging (MRI) measurements in locally advanced oestrogen receptor-positive and human epidermal growth factor receptor 2-negative breast tumours before, during and after neoadjuvant endocrine treatment (NET) for evaluation of tumour response in comparison with clinical and pathological assessments.

Methods

This prospective study enrolled postmenopausal patients treated neoadjuvant with letrozole and exemestane given sequentially in an intra-patient cross-over regimen. Fifty-four patients were initially recruited, but only 35 fulfilled the inclusion criteria and confirmed to participate with a median age of 77. Tumours were scanned with MRI prior to treatment, during the eighth week of treatment and prior to surgery. Additionally, changes in longest diameter on clinical examination (CE) and tumour size at pathology were determined. Pre- and post-operative measurements of tumour size were compared in order to evaluate tumour response.

Results

The correlation between post-treatment MRI size and pathology was moderate and higher with a correlation coefficient (r) 0.64 compared to the correlation between CE and pathology r = 0.25. Post-treatment MRI and clinical results had a negligible bias towards underestimation of lesion size. Tumour size on MRI and CE had 0.82 cm and 0.52 cm lower mean size than tumour size measured by pathology, respectively.

Conclusions

The higher correlation between measurements of residual disease obtained on MRI and those obtained with pathology validates the accuracy of imaging assessment during NET. MRI was found to be more accurate for estimating complete responses than clinical assessments and warrants further investigation in larger cohorts to validate this finding.

Electronic supplementary material

The online version of this article (10.1007/s10549-020-05852-7) contains supplementary material, which is available to authorized users.

Factors affecting the concordance of radiologic and pathologic tumor size in breast carcinoma

Background

Radiologic assessment of tumor size is an integral part of the work-up for breast carcinoma. With improved radiologic equipment, surgical decision relies profoundly upon radiologic/clinical stage. We wanted to see the concordance between radiologic and pathologic tumor size to infer how accurate radiologic/clinical staging is.

Materials and methods

The surgical pathology and ultrasonography reports of patients with breast carcinoma were reviewed. Data were collected for 406 cases. Concordance was defined as a size difference within ±2 mm.

Results

The difference between radiologic and pathologic tumor size was within ±2 mm in 40.4% cases. The mean radiologic size was 1.73 ± 1.06 cm. The mean pathologic size was 1.84 ± 1.24 cm. A paired t-test showed a significant mean difference between radiologic and pathologic measurements (0.12 ± 1.03 cm, p = 0.03). Despite the size difference, stage classification was the same in 59.9% of cases. Radiologic size overestimated stage in 14.5% of cases and underestimated stage in 25.6% of cases. The concordance rate was significantly higher for tumors ≤2 cm (pT1) (51.1%) as compared to those greater than 2 cm (≥pT2) (19.7%) (p < 0.0001). Significantly more lumpectomy specimens (47.5%) had concordance when compared to mastectomy specimens (29.8%) (p < 0.0001). Invasive ductal carcinoma had better concordance compared to other tumors (p = 0.02).

Conclusion

Mean pathologic tumor size was significantly different from mean radiologic tumor size. Concordance was in just over 40% of cases and the stage classification was the same in about 60% of cases only. Therefore, surgical decision of lumpectomy versus mastectomy based on radiologic tumor size may not always be accurate.

Tumor Size in Breast Carcinoma: Gross Measurement Is Important!

Introduction. The staging of breast carcinoma is mainly dependent on tumor size and lymph node status. Small increments in tumor size upstage the patient. An accurate determination of the tumor size is therefore critically important. Although the final staging is based on microscopic size, pathologists rely on gross measurements in a considerable number of cases. Methods. We investigated the concordance between gross and microscopic measurements of breast carcinoma as well as factors affecting this concordance. This study is a retrospective review of surgical pathology reports of invasive breast carcinomas. Data were collected for 411 cases. Concordance was defined as a size difference within ±2 mm. Results. Gross and microscopic sizes were identical in 33.1% of cases. Gross and microscopic size difference was within ±2 mm in 56% of cases. Despite the size difference, stage classification ended up being the same in 68.6% of cases. Tumor stage was over estimated by gross measurement in 17.0% of cases and underestimated in 14.4% of cases. The concordance was significantly higher for those tumors in which final pathologic tumor (pT) size was greater than 2 cm (≥pT2) as compared with those less than or equal to 2 cm (≤pT1; P < .0001). A higher proportion of mastectomy specimens (61.4%) were concordant as compared with lumpectomy specimens (52.1%). Conclusion. Gross and microscopic tumor sizes were concordant in 56% of cases. Stage classification based on gross and microscopic tumor size was different in nearly one third (31.4%) of cases. Gross tumor size is critically important in accurate staging at least in cases where tumor size cannot be confirmed microscopically.

Role of Magnetic Resonance Imaging in Detection of Pathologic Complete Remission in Breast Cancer Patients Treated With Neoadjuvant Chemotherapy: A Meta-analysis

Pathologic complete remission after neoadjuvant chemotherapy has a role in guiding the management of breast cancer. The present meta-analysis examined the accuracy of contrast-enhanced magnetic resonance imaging (CE-MRI) and diffusion-weighted magnetic resonance imaging (DW-MRI) in detecting the response to neoadjuvant chemotherapy and compared CE-MRI with ultrasonography, mammography, and positron emission tomography/computed tomography (PET/CT). Medical subject heading terms and related keywords were searched to generate a compilation of eligible studies. The pooled sensitivity, specificity, diagnostic odds ratio, area under summary receiver operating characteristic curve (AUC), and Youden index (Q* index) were used to estimate the diagnostic efficacy of CE-MRI, DW-MRI, ultrasonography, mammography, and PET/CT. A total of 54 studies of CE-MRI and 8 studies of DW-MRI were included. The overall AUC and the Q* index values for CE-MRI and DW-MRI were 0.88 and 0.94 and 0.80 and 0.85, respectively. According to the summary receiver operating characteristic curves, CE-MRI resulted in a higher AUC value and Q* index compared with ultrasonography and mammography but had values similar to those of DW-MRI and PET/CT. CE-MRI accurately assessed pathologic complete remission in specificity, and PET/CT and DW-MRI accurately assessed pathologic complete remission in sensitivity. The present meta-analysis indicates that CE-MRI has high specificity and DW-MRI has high sensitivity in predicting pathologic complete remission after neoadjuvant chemotherapy. CE-MRI is more accurate than ultrasonography or mammography. Additionally, PET/CT is valuable for predicting pathologic complete remission. CE-MRI, combined with PET/CT or DW-MRI, might allow for a more precise assessment of pathologic complete remission.

Survival is associated with complete response on MRI after neoadjuvant chemotherapy in ER-positive HER2-negative breast cancer

Background

Pathological complete remission (pCR) of estrogen receptor (ER)-positive/human epidermal growth factor receptor 2 (HER2)-negative breast cancer is rarely achieved after neoadjuvant chemotherapy (NAC). In addition, the prognostic value of pCR for this breast cancer subtype is limited. We explored whether response evaluation by magnetic resonance imaging (MRI) is associated with recurrence-free survival after NAC in ER-positive/HER2-negative breast cancer.

Methods

MRI examinations were performed in 272 women with ER-positive/HER2-negative breast cancer before, during and after NAC. MRI interpretation included lesion morphology at baseline, changes in morphology and size, and contrast uptake kinetics. These MRI features, clinical characteristics and final pathology were correlated with recurrence-free survival.

Results

The median follow up time was 41 months. There were 35 women with events, including 19 breast-cancer-related deaths. On multivariable analysis, age younger than 50 years (hazard ratio (HR) = 2.55, 95 % confidence interval (CI) 1.3, 5.02, p = 0.007), radiological complete response after NAC (HR = 14.11, CI 1.81, 1818; p = 0.006) and smaller diameters of washout/plateau enhancement at MRI after NAC (HR = 1.02, CI 1.00, 1.04, p = 0.036) were independently associated with best recurrence-free survival. Pathological response was not significant; HR = 2.12, CI 0.86, 4.64, p = 0.096.

Conclusions

MRI after NAC in ER-positive/HER2-negative tumors may be predictive of recurrence-free survival. A radiological complete response at MRI after NAC is associated with an excellent prognosis.

Diagnostic accuracy of MRI to evaluate tumour response and residual tumour size after neoadjuvant chemotherapy in breast cancer patients

Background

The aim, of the study was to estimate the accuracy of magnetic resonance imaging (MRI) in assessing residual disease in breast cancer patients receiving neoadjuvant chemotherapy (NAC) and to identify the clinico-pathological factors that affect the diagnostic accuracy of breast MRI to determine residual tumour size following NAC.

Patients and methods

91 breast cancer patients undergoing NAC (92 breast lesions) were included in the study. Breast MRI was performed at baseline and after completion of NAC. Treatment response was evaluated by MRI and histopathological examination to investigate the ability of MRI to predict tumour response. Residual tumour size was measured on post-treatment MRI and compared with pathology in 89 lesions. Clinicopathological factors were analyzed to compare MRI-pathologic size differences.

Results

The overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for diagnosing invasive residual disease by using MRI were 75.00%, 78.57%, 88.89%, 57.89%, and 76.09% respectively. The Pearson’s correlation coefficient (r) between tumour sizes determined by MRI and pathology was r = 0.648 (p < 0.001). The size discrepancy was significantly lower in cancers with initial MRI size ≤ 5 cm (p = 0.050), in cancers with high tumour grade (p < 0.001), and in patients with hormonal receptor-negative cancer (p = 0.033).

Conclusions

MRI is an accurate tool for evaluating tumour response after NAC. The accuracy of MRI in estimating residual tumour size varies with the baseline MRI tumour size, the tumour grade and the hormonal receptor status.

Agreement between MRI and pathologic breast tumor size after neoadjuvant chemotherapy, and comparison with alternative tests: individual patient data meta-analysis

Background

Magnetic resonance imaging (MRI) may guide breast cancer surgery by measuring residual tumor size post-neoadjuvant chemotherapy (NAC). Accurate measurement may avoid overly radical surgery or reduce the need for repeat surgery. This individual patient data (IPD) meta-analysis examines MRI’s agreement with pathology in measuring the longest tumor diameter and compares MRI with alternative tests.

Methods

A systematic review of MEDLINE, EMBASE, PREMEDLINE, Database of Abstracts of Reviews of Effects, Heath Technology Assessment, and Cochrane databases identified eligible studies. Primary study authors supplied IPD in a template format constructed a priori. Mean differences (MDs) between tests and pathology (i.e. systematic bias) were calculated and pooled by the inverse variance method; limits of agreement (LOA) were estimated. Test measurements of 0.0 cm in the presence of pathologic residual tumor, and measurements >0.0 cm despite pathologic complete response (pCR) were described for MRI and alternative tests.

Results

Eight studies contributed IPD (N = 300). The pooled MD for MRI was 0.0 cm (LOA: +/−3.8 cm). Ultrasound underestimated pathologic size (MD: −0.3 cm) relative to MRI (MD: 0.1 cm), with comparable LOA. MDs were similar for MRI (0.1 cm) and mammography (0.0 cm), with wider LOA for mammography. Clinical examination underestimated size (MD: −0.8 cm) relative to MRI (MD: 0.0 cm), with wider LOA. Tumors “missed” by MRI typically measured 2.0 cm or less at pathology; tumors >2.0 cm were more commonly “missed” by clinical examination (9.3 %). MRI measurements >5.0 cm occurred in 5.3 % of patients with pCR, but were more frequent for mammography (46.2 %).

Conclusions

There was no systematic bias in MRI tumor measurement, but LOA are large enough to be clinically important. MRI’s performance was generally superior to ultrasound, mammography, and clinical examination, and it may be considered the most appropriate test in this setting. Test combinations should be explored in future studies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1664-4) contains supplementary material, which is available to authorized users.

Combination of letrozole, metronomic cyclophosphamide and sorafenib is well-tolerated and shows activity in patients with primary breast cancer

PURPOSE

To assess whether the combination of letrozole, metronomic cyclophosphamide and sorafenib (LCS) is well tolerated and shows activity in primary breast cancer (BC).

METHODS

Thirteen oestrogen receptor-positive, postmenopausal, T2-4, N0-1 BC patients received the LCS combination for 6 months. In these patients we examined the pharmacokinetics of sorafenib and cyclophosphamide, toxicity of the regimen, the clinical response to therapy and changes in the levels of biologically relevant biomarkers.

RESULTS

Adequate plasma concentrations of sorafenib were achieved in patients when it was dosed in combination with L+C. The mean plasma concentrations of C were consistently lower following administration of LCS, compared with administration of L+C only. The most common drug-related grade 3/4 adverse events were skin rash (69.3%), hand-foot skin reaction (69.3%) and diarrhoea (46.1%). According to RECIST Criteria, a clinical complete response was observed in 6 of 13 patients. A significant reduction in tumour size, evaluated with MRI, was also observed between baseline and 14 days of treatment in all 13 patients (P=0.005). A significant reduction in SUV uptake, measured by (18)FDG-PET/CT, was observed in all patients between baseline and 30 days of treatment (P=0.015) and between baseline and definitive surgery (P=0.0002). Using modified CT Criteria, a response was demonstrated in 8 out of 10 evaluable patients at 30 days and in 11 out of 13 evaluable patients at the definitive surgery. A significant reduction in Ki67 expression was observed in all patients at day 14 compared with baseline (P<0.00001) and in 9 out of 13 patients at the definitive surgery compared with baseline (P<0.03). There was also a significant suppression of CD31 and VEGF-A expression in response to treatment (P=0.01 and P=0.007, respectively).

CONCLUSIONS

The LCS combination is feasible and tolerable. The tumour response and target biomarker modulation indicate that the combination is clinically and biologically active.

Sentinel node biopsy after neoadjuvant chemotherapy in cytologically proven node-positive breast cancer

INTRODUCTION

Several studies have assessed the feasibility of sentinel lymph node biopsy (SLNB) after NAC in patients with breast cancer, but diagnostic accuracy has varied. We prospectively evaluated the diagnostic accuracy of SLNB in detecting axillary lymph node (ALN) metastases after NAC in patients with cytologically proven positive nodes before chemotherapy.

PATIENTS AND METHODS

We studied 95 breast cancer patients with cytologically proven positive nodes and a partial or complete clinical response to NAC in the breast lesions confirmed using magnetic resonance imaging. Patients then underwent SLNB followed by ALN dissection. The identification rate of sentinel lymph nodes (SLNs) and the false negative rate of nodal metastases were assessed. Subgroup analysis was conducted according to several clinical factors.

RESULTS

SLNs were successfully identified in 81 (85.3%) of the 95 patients. Among these 81 patients, 51 (63.0%) had ALN metastases on final pathologic examination after NAC. Eight of the 51 patients with ALN metastases had negative results on SLNB (false negative rate, 15.7%). Univariate analysis indicated that the false negative rate was significantly lower only in the HER2-negative group (P = .003).

CONCLUSION

SLNB after NAC did not correctly predict the presence or absence of axillary node metastases in patients with breast cancer who had cytologically proven positive nodes before NAC. However, the diagnostic accuracy might be different in cancer subtypes, therapeutic effect of chemotherapy, or sentinel lymph node status after chemotherapy. Well-powered studies are needed to confirm diagnostic accuracy of SLNB after NAC according to subgroup in patients with breast cancer.

Changes in primary breast cancer heterogeneity may augment midtreatment MR imaging assessment of response to neoadjuvant chemotherapy

PURPOSE

To evaluate whether changes in magnetic resonance (MR) imaging heterogeneity may aid assessment for pathologic complete response (pCR) to neoadjuvant chemotherapy (NACT) in primary breast cancer and to compare pCR with standard Response Evaluation Criteria in Solid Tumors response.

MATERIALS AND METHODS

Institutional review board approval, with waiver of informed consent, was obtained for this retrospective analysis of 36 consecutive female patients, with unilateral unifocal primary breast cancer larger than 2 cm in diameter who were receiving sequential anthracycline-taxane NACT between October 2008 and October 2012. T2- and T1-weighted dynamic contrast material-enhanced MR imaging was performed before, at midtreatment (after three cycles), and after NACT. Changes in tumor entropy (irregularity) and uniformity (gray-level distribution) were determined before and after MR image filtration (for different-sized features). Entropy and uniformity for pathologic complete responders and nonresponders were compared by using the Mann-Whitney U test and receiver operating characteristic analysis.

RESULTS

With NACT, there was an increase in uniformity and a decrease in entropy on T2-weighted and contrast-enhanced subtracted T1-weighted MR images for all filters (uniformity: 23.45% and 22.62%; entropy: -19.15% and -19.26%, respectively). There were eight complete pathologic responders. An area under the curve of 0.84 for T2-weighted MR imaging entropy and uniformity (P = .004 and .003) and 0.66 for size (P = .183) for pCR was found, giving a sensitivity and specificity of 87.5% and 82.1% for entropy and 87.5% and 78.6% for uniformity compared with 50% and 82.1%, respectively, for tumor size change for association with pCR.

CONCLUSION

Tumors become more homogeneous with treatment. An increase in T2-weighted MR imaging uniformity and a decrease in T2-weighted MR imaging entropy following NACT may provide an earlier indication of pCR than tumor size change.

Meta-analysis of agreement between MRI and pathologic breast tumour size after neoadjuvant chemotherapy

BACKGROUND

Magnetic resonance imaging (MRI) has been proposed to guide breast cancer surgery by measuring residual tumour after neoadjuvant chemotherapy. This study-level meta-analysis examines MRI's agreement with pathology, compares MRI with alternative tests and investigates consistency between different measures of agreement.

METHODS

A systematic literature search was undertaken. Mean differences (MDs) in tumour size between MRI or comparator tests and pathology were pooled by assuming a fixed effect. Limits of agreement (LOA) were estimated from a pooled variance by assuming equal variance of the differences across studies.

RESULTS

Data were extracted from 19 studies (958 patients). The pooled MD between MRI and pathology from six studies was 0.1 cm (95% LOA: -4.2 to 4.4 cm). Similar overestimation for MRI (MD: 0.1 cm) and ultrasound (US) (MD: 0.1 cm) was observed, with comparable LOA (two studies). Overestimation was lower for MRI (MD: 0.1 cm) than mammography (MD: 0.4 cm; two studies). Overestimation by MRI (MD: 0.1 cm) was smaller than underestimation by clinical examination (MD: -0.3 cm). The LOA for mammography and clinical examination were wider than that for MRI. Percentage agreement between MRI and pathology was greater than that of comparator tests (six studies). The range of Pearson's/Spearman's correlations was wide (0.21-0.92; 16 studies). Inconsistencies between MDs, percentage agreement and correlations were common.

CONCLUSION

Magnetic resonance imaging appears to slightly overestimate pathologic size, but measurement errors may be large enough to be clinically significant. Comparable performance by US was observed, but agreement with pathology was poorer for mammography and clinical examination. Percentage agreement can provide supplementary information to MDs and LOA, but Pearson's/Spearman's correlation does not provide evidence of agreement and should be avoided. Further comparisons of MRI and other tests using the recommended methods are warranted.

Meta-analysis of magnetic resonance imaging in detecting residual breast cancer after neoadjuvant therapy

BACKGROUND

It has been proposed that magnetic resonance imaging (MRI) be used to guide breast cancer surgery by differentiating residual tumor from pathologic complete response (pCR) after neoadjuvant chemotherapy. This meta-analysis examines MRI accuracy in detecting residual tumor, investigates variables potentially affecting MRI performance, and compares MRI with other tests.

METHODS

A systematic literature search was undertaken. Hierarchical summary receiver operating characteristic (HSROC) models were used to estimate (relative) diagnostic odds ratios ([R]DORs). Summary sensitivity (correct identification of residual tumor), specificity (correct identification of pCR), and areas under the SROC curves (AUCs) were derived. All statistical tests were two-sided.

RESULTS

Forty-four studies (2050 patients) were included. The overall AUC of MRI was 0.88. Accuracy was lower for "standard" pCR definitions (referent category) than "less clearly described" (RDOR = 2.41, 95% confidence interval [CI] = 1.11 to 5.23) or "near-pCR" definitions (RDOR = 2.60, 95% CI = 0.73 to 9.24; P = .03.) Corresponding AUCs were 0.83, 0.90, and 0.91. Specificity was higher when negative MRI was defined as contrast enhancement less than or equal to normal tissue (0.83, 95% CI = 0.64 to 0.93) vs no enhancement (0.54, 95% CI = 0.39 to 0.69; P = .02), with comparable sensitivity (0.83, 95% CI = 0.69 to 0.91; vs 0.87, 95% CI = 0.80 to 0.92; P = .45). MRI had higher accuracy than mammography (P = .02); there was only weak evidence that MRI had higher accuracy than clinical examination (P = .10). No difference in MRI and ultrasound accuracy was found (P = .15).

CONCLUSIONS

MRI accurately detects residual tumor after neoadjuvant chemotherapy. Accuracy was lower when pCR was more rigorously defined, and specificity was lower when test negativity thresholds were more stringent; these definitions require standardization. MRI is more accurate than mammography; however, studies comparing MRI and ultrasound are required.

Can diffusion-weighted MR imaging and contrast-enhanced MR imaging precisely evaluate and predict pathological response to neoadjuvant chemotherapy in patients with breast cancer?

Clinical evidence regarding the value of MRI for therapy responses assessment in breast cancer is increasing. The objective of this study is to compare the diagnostic capability of diffusion-weighted MR imaging (DW-MRI) and contrast-enhanced MR imaging (CE-MRI) to evaluate and predict pathological response in breast cancer patients receiving neoadjuvant chemotherapy (NAC). We performed a meta-analysis of all available studies of the diagnostic performance of DW-MRI or CE-MRI to evaluate and predict pathological response to NAC in patients with breast cancer. We determined sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR+ and LR-), diagnostic odds ratio (DOR) and constructed summary receiver operating characteristic curves using hierarchical regression models. Methodological quality was assessed by QUADAS tool. Thirty-four studies met the inclusion criteria and involved 1,932 pathologically confirmed patients in total. Methodological quality was relatively high. DW-MRI sensitivity was 0.93 (95 % CI 0.82-0.97) and specificity was 0.82 (95 % CI 0.70-0.90). Overall LR+ was 5.09 (95 % CI 3.09-8.38), LR- was 0.09 (95 % CI 0.04-0.22), and DOR was 55.59 (95 % CI 21.80-141.80). CE-MRI sensitivity was 0.68 (95 % CI 0.57-0.77) and specificity was 0.91 (95 % CI 0.87-0.94). Overall LR+ was 7.48 (95 % CI 5.29-10.57), LR- was 0.36 (95 % CI 0.27-0.48), and DOR was 20.98 (95 % CI 13.24-33.24). Our study confirms that DW-MRI is a high sensitive and CE-MRI is a high specific modality in predicting pathological response to NAC in breast cancer patients. The combined use of DW-MRI and CE-MRI has the potential to improve the diagnostic performance in monitoring NAC. Further large prospective studies are warranted to assess the actual value of this combination in breast cancer preoperative treatment screening.

Breast Cancer Tumor Size Assessment with Mammography, Ultrasonography, and Magnetic Resonance Imaging at a Community Based Multidisciplinary Breast Center

Paramount to staging and patient management is accurately measuring the size of invasive breast cancers. We assessed the accuracy of mammography (MG), ultrasonography (US), and magnetic resonance imaging (MRI) at our community-based hospital in which multiple radiologists and imaging machines are used in the care of our patients. We performed a retrospective analysis of a prospectively maintained database of 277 patients seen at our breast center from 2009 to 2010. We tabulated MG, US, and MRI-reported tumor sizes in 161 women with pathology-proven invasive breast cancer and compared the preoperative size measurements with final pathologic tumor size. In the 161 patients, 169 lesions were identified. Imaging using all three modalities was available in 47 patients. When compared with final pathology, MRI had a correlation of r = 0.75 to mean tumor size as compared with US (r = 0.67) and MG (r = 0.76). Mean tumor size was 1.90 cm by MG, 1.87 cm by US, 2.40 cm by MRI, and 2.19 cm by pathology. We were able to achieve an excellent correlation of pathologic tumor size to preoperative imaging. The absolute differences in size between the modalities were small. MRI, in select patients, added to the assessment of tumor size based on US and MG.

MRI in breast cancer therapy monitoring

Breast MRI has several roles in the clinical management of breast cancer, including as a screening method for high-risk women, as a diagnostic tool used as an adjunct to mammography and ultrasound, and for the staging of disease extent prior to treatment. In addition to these uses, MRI is also employed to track small changes in tumor size and microenvironment. MRI has produced several early indicators of treatment response in clinical trials over the last 10  years, including initial lesion pattern, changes in lesion size, kinetic parameters, apparent diffusion coefficient and T(2) value; the related technique of (1) H MRS has also shown that choline concentration, T(2) value and water-to-fat ratio are response indicators. In addition to measuring anatomical changes in the lesion size, as performed in traditional radiology, MRI has the ability to track vascular and cellular changes using dynamic contrast-enhanced MRI and diffusion-weighted MRI, respectively. By adding (1) H MRS to MRI examinations, metabolic changes can also be determined. These functional imaging techniques allow studies to focus on early time points relative to neoadjuvant treatment. Early treatment response predictors may allow therapy to be tailored to individual patients and thus aid in the realization of the goal of personalized medicine.

Accuracy of MRI in prediction of pathologic complete remission in breast cancer after preoperative therapy: a meta-analysis

OBJECTIVE

Prediction of pathologic complete remission in breast cancer after preoperative therapy presents difficulties. We performed a meta-analysis to determine the ability of MRI to predict pathologic complete remission in patients with breast cancer after preoperative therapy.

MATERIALS AND METHODS

Medical subject heading terms ("MRI" and "Breast Neoplasm") and key words ("neoadjuvant" or "primary systemic" or "preoperative" or "presurgery") were used for a literature search in the MEDLINE database. A meta-analysis of pooled data from eligible studies was performed to estimate the accuracy of MRI in predicting pathologic complete remission after preoperative therapy in patients with breast cancer.

RESULTS

Twenty-five studies were included in this meta-analysis. Pooled weighted estimates of sensitivity and specificity were 0.63 (range, 0.56-0.70) and 0.91 (range, 90.89-0.92), respectively. Heterogeneity between studies was highly influenced by the pathologic complete remission rate, with a regression coefficient of -6.160 (p = 0.020). Subgroup analysis showed that the specificity of MRI in studies with a pathologic complete remission rate of > or = 20% was lower than that in studies with a pathologic complete remission rate of < 20% (p = 0.0003).

CONCLUSION

This meta-analysis indicates that MRI has high specificity and relatively lower sensitivity in predicting pathologic complete remission after preoperative therapy in patients with breast cancer. The pathologic complete remission rate may influence the performance of MRI accuracy in this setting, which deserves further investigation.

MRI versus Ultrasonography and Mammography for Preoperative Assessment of Breast Cancer

Mammography and ultrasonography are traditional for preoperative estimation of breast cancer size; magnetic resonance imaging (MRI) is more recent but not as well studied. We compared ultrasonography, mammography, and MRI for preoperative imaging of primary breast cancer presenting as a mass in patients treated at our center over a 2-year period. Of the 61 breast cancers with all three imaging modalities performed, 52 were infiltrating ductal cancer, 5 were infiltrating lobular cancer, 2 were ductal carcinoma in situ, and 2 were other histologic types. When pathologic size was used to determine the accuracy of imaging assessments, the Pearson correlation coefficient was better for MRI (r = 0.80) than ultrasonography (r = 0.57) or mammography (r = 0.26). Mean tumor size was 2.1 cm by mammography, 1.73 cm by ultrasonography, 2.65 cm by MRI, and 2.76 cm by pathology. MRI-based tumor size was within 1 cm of pathologic size in 44 (72%) tumors, > 1 cm above pathologic size in 6 (10%) tumors, and > 1 cm below pathologic size in 11 (18%) tumors. We conclude that MRI is more accurate than either ultrasonography or mammography for assessment of the size of primary breast cancer presenting as a mass.

Impact of MRI-evaluated neoadjuvant chemotherapy response on change of surgical recommendation in breast cancer

OBJECTIVE

To investigate how MRI imaging of neoadjuvant chemotherapy (NAC) tumor response affects the recommendation for optimal breast cancer surgery, both before and after NAC.

SUMMARY BACKGROUND DATA

Understanding how imaging findings are incorporated into surgeons' decision-making processes will help establish appropriate imaging guidelines for recommending breast conservation surgery (BCS) after the NAC.

METHODS

Seventy-six breast cancer patients undergoing NAC with MRI follow-up studies were analyzed. Two experienced breast surgeons reviewed all cases. An initial surgical recommendation was made based on the pre-NAC lesion presentation; a subsequent surgical recommendation was made based on the post-NAC tumor response. Finally, the pathology results were disclosed and the surgeons were asked to decide on the optimal definitive surgical procedure. MRI findings throughout the entire course of the NAC were analyzed to understand how they affected different recommendations.

RESULTS

Before the NAC, a large tumor size or extent of disease were the primary determinant factors for mastectomy. In this study, the mean tumor size was 5.3 +/- 3.4 cm (RECIST) in the mastectomy group and 3.2 +/- 1.6 cm in the lumpectomy group (P = 0.0001). After the NAC, based on consensus recommendations, 21 mastectomy candidates remained for mastectomy, with tumor size decreasing from 7.4 +/- 4.5 to 1.5 +/- 2.5 cm, and 22 mastectomy candidates were changed to lumpectomy, with tumor size decreasing from 4.2 +/- 2.1 to 0.4 +/- 0.6 cm. When the final pathology revealed pCR or minimal residual disease, the surgeons agreed that BCS is the optimal procedure. On the other hand, for a large extent of residual disease, mastectomy should be performed.

CONCLUSION

In patients who had more extensive pretreatment disease, despite an excellent response to NAC, the surgeons still tended to apply an aggressive approach and recommended mastectomy. Given that the confirmation of pCR or minimal residual disease would change surgeons' recommendations for less aggressive, conservation surgery, the maturity of MRI for NAC response prediction may provide reliable staging information to aid in the recommendation of the optimal surgical procedure.

Current Status of Breast MR Imaging Part 2. Clinical Applications

Magnetic resonance (MR) imaging is emerging as the most sensitive modality that is currently available for the detection of primary or recurrent breast cancer. Although this technique has been shown to be an extremely powerful diagnostic tool, it is still relatively rarely used in clinical practice, as compared with other applications of MR imaging such as for musculoskeletal or brain and spine imaging. This is the second of a two-part series on the current status of breast MR. Part two provides an overview of the use of breast MR imaging in clinical patient care, the body of evidence that supports its use. A discussion is provided on the many controversies that exist regarding breast MR imaging for preoperative staging and for screening.

The accuracy of ultrasonic indentation in detecting simulated bone displacement: a comparison of three techniques

PURPOSE

Palpation is used most commonly to assess tissue stiffness despite its well-known deficiencies. As an improvement, a mechanical technique known as ultrasonic indentation has been proposed. The purpose of this study was to compare the accuracy of 3 ultrasonic indentation techniques in quantifying bone displacement in a specially constructed tissue simulator.

METHODS

Three ultrasonic indentation techniques were tested for their accuracy: a rigid, laboratory-based method (rigid), a less rigid system actuated by hand (assisted), and a totally free-hand system (handheld). Each indentation technique was applied on a tissue simulator, which consisted of a deformable phantom overlying a displaceable piston to simulate soft tissue overlying bone. Measures of piston (ie, bone) displacement obtained by each indentation technique were compared with a gold standard of piston displacement to determine the accuracy of each technique. Statistical tests were used to determine if differences between experimental and reference measures of piston displacement were significant.

RESULTS

When indented, phantom deformation preceded piston displacement because of unequal stiffness between the two. The rigid and assisted indentation techniques showed the best accuracy for measuring simulated bone displacement. Differences in accuracy between the rigid and assisted techniques were insignificant. The accuracy of the handheld technique was significantly less than the rigid and assisted techniques.

CONCLUSIONS

The clinical utility of assisted ultrasonic indentation should be explored given its accuracy and the excessive size, cost, and complexity of the rigid technique. The large error magnitude of the handheld technique may exclude it from clinical use now.