Hye Ryoung Koo

Correlation of perfusion parameters on dynamic contrast-enhanced MRI with prognostic factors and subtypes of breast cancers.

To investigate whether a correlation exists between perfusion parameters obtained from dynamic contrast‐enhanced (DCE) magnetic resonance imaging (MRI) and prognostic factors or immunohistochemical subtypes of breast cancers.

Breast Cancer Detected with Screening US: Reasons for Nondetection at Mammography

PURPOSE To retrospectively review the mammograms of women with breast cancers detected at screening ultrasonography (US) to determine the reasons for nondetection at mammography. MATERIALS AND METHODS This study received institutional review board approval, and informed consent was waived. Between 2003 and 2011, a retrospective database review revealed 335 US-depicted cancers in 329 women (median age, 47 years; age range, 29-69 years) with Breast Imaging Reporting and Data System breast density type 2-4. Five blinded radiologists independently reviewed the mammograms to determine whether the findings on negative mammograms should be recalled. Three unblinded radiologists re-reviewed the mammograms to determine the reasons for nondetection by using the reference location of the cancer on mammograms obtained after US-guided wire localization or breast magnetic resonance imaging. The number of cancers recalled by the blinded radiologists were compared with the reasons for nondetection determined by the unblinded radiologists. RESULTS Of the 335 US-depicted cancers, 63 (19%) were recalled by three or more of the five blinded radiologists, and 272 (81%) showed no mammographic findings that required immediate action. In the unblinded repeat review, 263 (78%) cancers were obscured by overlapping dense breast tissue, and nine (3%) were not included at mammography owing to difficult anatomic location or poor positioning. Sixty-three (19%) cancers were considered interpretive errors. Of these, 52 (82%) were seen as subtle findings (46 asymmetries, six calcifications) and 11 (18%) were evident (six focal asymmetries, one distortion, four calcifications). CONCLUSION Most breast cancers (81%) detected at screening US were not seen at mammography, even in retrospect. In addition, 19% had subtle or evident findings missed at mammography.

Sonoelastography for 1786 non-palpable breast masses: diagnostic value in the decision to biopsy

AbstractObjectivesTo evaluate the diagnostic value of sonoelastography by correlation with histopathology compared with conventional ultrasound on the decision to biopsy.MethodsProspectively determined BI-RADS categories of conventional ultrasound and elasticity scores from strain sonoelastography of 1786 non-palpable breast masses (1,523 benign and 263 malignant) in 1,538 women were correlated with histopathology. The sensitivity and specificity of two imaging techniques were compared regarding the decision to biopsy. We also investigated whether there was a subset of benign masses that were recommended for biopsy by B-mode ultrasound but that had a less than 2% malignancy rate with the addition of sonoelastography.ResultsThe mean elasticity score of malignant lesions was higher than that of benign lesions (2.94 ± 1.10 vs. 1.78 ± 0.81) (P < 0.001). In the decision to biopsy, B-mode ultrasound had higher sensitivity than sonoelastography (98.5% vs. 93.2%) (P < 0.001), whereas sonoelastography had higher specificity than B-mode ultrasound (42.6% vs. 16.3%) (P < 0.001). BI-RADS category 4a lesions with an elasticity score of 1 had a malignancy rate of 0.8%.ConclusionsSonoelastography has higher specificity than B-mode ultrasound in the differentiation between benign and malignant masses and has the potential to reduce biopsies with benign results.Key Points• Sonoelastography has higher specificity than B-mode ultrasound in distinguishing benign from malignant masses.• Sonoelastography could potentially help reduce the number of biopsies with benign results. • Lesion stiffness on sonoelastography correlated with the malignant potential of the lesion.

Added Value of Shear-Wave Elastography for Evaluation of Breast Masses Detected with Screening US Imaging

PURPOSE To evaluate the additional value of shear-wave elastography (SWE) to B-mode ultrasonography (US) and to determine an appropriate guideline for the combined assessment of screening US-detected breast masses. MATERIALS AND METHODS This study was conducted with institutional review board approval, and written informed consent was obtained. From March 2010 to February 2012, B-mode US and SWE were performed in 159 US-detected breast masses before biopsy. For each lesion, Breast Imaging Reporting and Data System (BI-RADS) category on B-mode US images and the maximum stiffness color and elasticity values on SWE images were assessed. A guideline for adding SWE data to B-mode US was developed with the retrospective cohort to improve diagnostic performance in sensitivity and specificity and was validated in a distinct prospective cohort of 207 women prior to biopsy. RESULTS Twenty-one of 159 masses in the development cohort and 12 of 207 breast masses in the validation cohort were malignant. In the development cohort, when BI-RADS category 4a masses showing a dark blue color or a maximum elasticity value of 30 kPa or less on SWE images were downgraded to category 3, specificity increased from 9.4% (13 of 138) to 59.4% (82 of 138) and 57.2% (79 of 138) (P < .001), respectively, without loss in sensitivity (100% [21 of 21]). In the validation cohort, specificity increased from 17.4% (34 of 195) to 62.1% (121 of 195) and 53.3% (104 of 195) (P < .001) respectively, without loss in sensitivity (91.7% [11 of 12]). CONCLUSION The addition of SWE to B-mode US improved diagnostic performance with increased specificity for screening US-detected breast masses. BI-RADS category 4a masses detected at US screening that showed a dark blue color or a maximum elasticity value of 30 kPa or less on SWE images can be safely followed up instead of performing biopsy.

Practice guideline for the performance of breast ultrasound elastography

Ultrasound (US) elastography is a valuable imaging technique for tissue characterization. Two main types of elastography, strain and shear-wave, are commonly used to image breast tissue. The use of elastography is expected to increase, particularly with the increased use of US for breast screening. Recently, the US elastographic features of breast masses have been incorporated into the 2nd edition of the Breast Imaging Reporting and Data System (BI-RADS) US lexicon as associated findings. This review suggests practical guidelines for breast US elastography in consensus with the Korean Breast Elastography Study Group, which was formed in August 2013 to perform a multicenter prospective study on the use of elastography for US breast screening. This article is focused on the role of elastography in combination with B-mode US for the evaluation of breast masses. Practical tips for adequate data acquisition and the interpretation of elastography results are also presented.

Unilateral breast cancer: screening of contralateral breast by using preoperative MR imaging reduces incidence of metachronous cancer.

PURPOSE To investigate the clinical effect of a single magnetic resonance (MR) imaging screening examination of the contralateral breast at preoperative evaluation in women with unilateral breast cancer. MATERIALS AND METHODS The institutional review board approved this study and waived informed consent. Among women with unilateral breast cancer who underwent curative surgery from 2004 to 2008, 1323 women (mean age, 46.8 years; range, 18-81 years) underwent mammography and ultrasonography (US) alone (comparison group) between January 2004 and December 2006; 1771 consecutive women (mean age, 48.2 years; range, 22-85 years) underwent mammography, US, and MR imaging (contralateral MR imaging-screened group) between January 2007 and December 2008. The incidence of synchronous cancer and the incidence of metachronous cancer in the contralateral breast were compared between groups. Multivariate Cox analysis was performed. Median follow-up was 56 months (range, 13-94 months). RESULTS Twenty-five synchronous contralateral cancers (13 invasive cancers, 12 ductal carcinomas in situ; mean invasive size, 14 mm [range, 1-35 mm]; 92% [12 of 13] of invasive tumors were node negative) were additionally detected with MR imaging in the MR imaging-screened group. The cumulative incidence of contralateral breast cancer at 45 months was 0.5% (nine of 1771) (95% confidence interval [CI]: 0.23%, 0.96%) for the MR imaging-screened group and 1.4% (18 of 1323) (95% CI: 0.81%, 2.14%) for the comparison group (P = .02). Contralateral MR imaging screening (hazard ratio, 0.37; 95% CI: 0.15, 0.92; P = .03) and estrogen receptor negativity (hazard ratio, 3.98; 95% CI: 1.60, 9.92; P = .003) were associated with risk of contralateral cancer diagnosis in multivariate analysis. CONCLUSION A single MR imaging screening examination of the contralateral breast in women with unilateral breast cancer increased synchronous cancer detection and was associated with decreased diagnosis of metachronous contralateral cancer within 45 months.

Characteristics of breast cancers detected by ultrasound screening in women with negative mammograms

Screening ultrasound (US) can increase the detection of breast cancer. However, little is known about the clinicopathologic characteristics of breast cancers detected by screening US. A search of the database for patients with breast cancer yielded a dataset in 6837 women who underwent breast surgery at Seoul National University Hospital (Korea). Of 6837 women, 1047 were asymptomatic and had a non‐palpable cancer. Two hundred fifty‐four women with 256 cancers detected by US (US‐detected cancer) and 793 women with 807 cancers detected by mammography (MG‐detected cancer) were identified. The imaging, clinicopathologic, and molecular data were reviewed. Univariate and multivariate analyses were carried out. Women with US‐detected cancer were younger and were more likely to undergo breast‐conserving surgery and to have node‐negative invasive cancer (P < 0.0001). By multivariate analysis, the significant independent characteristics were tumor size, mammographic density, final assessment category according to the American College of Radiology Breast Imaging Reporting and Data System, progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and molecular subtype. Compared to tumors that were >2 cm in size, tumors that were ≤1 cm in size were 2.2‐fold more likely to be US‐detected cancers (P = 0.02). Compared to the luminal A subtype tumors (estrogen receptor [ER]+, PR+, HER2−), luminal B subtype tumors (ER+, PR+, HER2 + ) were less likely to be in the US‐detected cancer group (P < 0.01). Women with dense breasts were more likely to have US‐detected cancer (P < 0.01) versus those with non‐dense breasts. Screening US‐detected cancers were less likely to be diagnosed as category 5 instead of category 4 (P < 0.01). In conclusion, women with US‐detected breast cancer are more likely to have small‐sized invasive cancer and more likely associated with the luminal A subtype. (Cancer Sci 2011; 102: 1862–1867)

Two-View versus Single-View Shear-Wave Elastography: Comparison of Observer Performance in Differentiating Benign from Malignant Breast Masses

PURPOSE To determine whether two-view shear-wave elastography (SWE) improves the performance of radiologists in differentiating benign from malignant breast masses compared with single-view SWE. MATERIALS AND METHODS This prospective study was conducted with institutional review board approval, and written informed consent was obtained. B-mode ultrasonographic (US) and orthogonal SWE images were obtained for 219 breast masses (136 benign and 83 malignant; mean size, 14.8 mm) in 219 consecutive women (mean age, 47.9 years; range, 20-78 years). Five blinded radiologists independently assessed the likelihood of malignancy for three data sets: B-mode US alone, B-mode US and single-view SWE, and B-mode US and two-view SWE. Interobserver agreement regarding Breast Imaging Reporting and Data System (BI-RADS) category and the area under the receiver operating characteristic curve (AUC) of each data set were compared. RESULTS Interobserver agreement was moderate (κ = 0.560 ± 0.015 [standard error of the mean]) for BI-RADS category assessment with B-mode US alone. When SWE was added to B-mode US, five readers showed substantial interobserver agreement (κ = 0.629 ± 0.017 for single-view SWE; κ = 0.651 ± 0.014 for two-view SWE). The mean AUC of B-mode US was 0.870 (range, 0.855-0.884). The AUC of B-mode US and two-view SWE (average, 0.928; range, 0.904-0.941) was higher than that of B-mode US and single-view SWE (average, 0.900; range, 0.890-0.920), with statistically significant differences for three readers (P ≤ .003). CONCLUSION The performance of radiologists in differentiating benign from malignant breast masses was improved when B-mode US was combined with two-view SWE compared with that when B-mode US was combined with single-view SWE.

Sonoelastographic lesion stiffness: preoperative predictor of the presence of an invasive focus in nonpalpable DCIS diagnosed at US-guided needle biopsy.

ObjectivesTo retrospectively evaluate whether sonoelastographic evaluation could help predict the presence of an invasive focus in nonpalpable DCIS diagnosed at US-guided needle biopsy.MethodsOne hundred and three consecutive nonpalpable DCIS lesions diagnosed at US-guided needle biopsy were analyzed. To identify the preoperative factors associated with upgrade to invasive cancers on surgical histology, lesion size, B-mode US findings, elasticity score, biopsy variables, and histological variables were analyzed using univariate and multivariate logistic regression. Interobserver agreement for the elasticity score was evaluated using the multi-rater κ statistics.ResultsThe overall upgrade rate was 23% (24 of 103). Elasticity score was found to be the only independent predictor of invasion. The upgrade rates according to the median elasticity score was 6.7% (1 of 15) for a score of 1, 20.6% (13 of 63) for a score of 2, and 40.0% (10 of 25) for a score of 3 (Odds ratio [OR] = 1; OR = 4.19, P = 0.207; OR = 12.32, P = 0.039, respectively). No association was found between other factors and the upgrade rate. The overall interobserver agreement for the elasticity score was moderate (κ = 0.587; P < .001).ConclusionsSonoelastographic lesion stiffness is an independent preoperative predictor of invasion in some patients with nonpalpable DCIS at US-guided needle biopsy.

Sonoelastography in Distinguishing Benign from Malignant Complex Breast Mass and Making the Decision to Biopsy

Objective To evaluate the additional effect of sonoelastography on the radiologists ability for distinguishing benign from malignant complex breast masses and to decide whether to perform biopsy by B-mode US. Materials and Methods One hundred eighteen complex breast masses (15 malignant lesions, 103 benign lesions) were included. Five blinded readers independently assessed the likelihood of the malignancy score from 1 to 5 for two data sets (B-mode ultrasound alone and B-mode ultrasound with sonoelastography). Elasticity scores were categorized as 0, 1, or 2 based on the degree and distribution of strain of the echogenic component within complex masses. The readers were asked to downgrade the likelihood of the malignancy score when an elasticity score of 0 was assigned and to upgrade the likelihood of the malignancy score when an elasticity score of 2 was assigned. The likelihood of the malignancy score was maintained as it was for the lesions with an elasticity score of 1. The Az values, sensitivities, and specificities were compared. Results The Az value of B-mode ultrasound with sonoelastography (mean, 0.863) was greater than that of B-mode ultrasound alone (mean, 0.731; p = 0.001-0.007) for all authors. The specificity of B-mode ultrasound with sonoelastography (mean, 37.1%) was greater than that of B-mode ultrasound alone (mean, 3.8%; p < 0.001) for all readers. The addition of sonoelastography led to changes in decisions. A mean of 33.6% of benign masses were recommended for follow-up instead of biopsy. Conclusion For complex breast masses, sonoelastography allows increase in both the accuracy in distinguishing benign from malignant lesions and the specificity in deciding whether to perform biopsy.