RESUMO
PURPOSE: To define the shear wave elastography (SWE) characteristics of breast cancer histological types by size in a large cohort. METHODS: Consecutive patients with US visible masses underwent SWE. All those with confirmed invasive breast cancer were included in the study. Histologic type was ascertained from core biopsy and surgical resection specimens. For each type, mean and median values for Emean and Emax were ascertained. Commoner tumour types were further analysed by invasive size. The significance of differences was established using the Chi-square test. RESULTS: 1137 tumours constituted the study group. The proportion of tumours with Emean below 50 kPa was higher in tubular cancers (23%) compared to ductal carcinomas of no specific type (DNST) (6%) (p < 0.001). Emax below 80 kPa was seen in 34% of tubular cancers compared to 16% of DNST (p < 0.002). Emean and Emax for lobular, mucinous, papillary and metaplastic cancers were not different from those of DNST. There were no significant differences in Emean or Emax between tumour types once broken down according to invasive size. CONCLUSIONS: Most breast cancer histological types have similar SWE characteristics. The exception is tubular cancer which has significantly lower stiffness than other histologic types, accounted for largely by their small size.
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Neoplasias da Mama/diagnóstico por imagem , Carcinoma Ductal de Mama/diagnóstico por imagem , Técnicas de Imagem por Elasticidade , Ultrassonografia Mamária , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia com Agulha de Grande Calibre , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e EspecificidadeRESUMO
OBJECTIVE: To establish if palpable breast masses with benign greyscale ultrasound features that are soft on shear-wave elastography (SWE) (mean stiffness <50 kPa) have a low enough likelihood of malignancy to negate the need for biopsy or follow-up. METHODS: The study group comprised 694 lesions in 682 females (age range 17-95 years, mean age 56 years) presenting consecutively to our institution with palpable lesions corresponding to discrete masses at ultrasound. All underwent ultrasound, SWE and needle core biopsy. Static greyscale images were retrospectively assigned Breast Imaging Reporting and Data System (BI-RADS) scores by two readers blinded to the SWE and pathology findings, but aware of the patient's age. A mean stiffness of 50 kPa was used as the SWE cut-off for calling a lesion soft or stiff. Histological findings were used to establish ground truth. RESULTS: No cancer had benign characteristics on both modalities. 466 (99.8%) of the 467 cancers were classified BI-RADS 4a or above. The one malignant lesion classified as BI-RADS 3 was stiff on SWE. 446 (96%) of the 467 malignancies were stiff on SWE. No cancer in females under 40 years had benign SWE features. 74 (32.6%) of the 227 benign lesions were BI-RADS 3 and soft on SWE; so, biopsy could potentially have been avoided in this group. CONCLUSION: Lesions which appear benign on greyscale ultrasound and SWE do not require percutaneous biopsy or short-term follow-up, particularly in females under 40 years. ADVANCES IN KNOWLEDGE: None of the cancers had benign characteristics on both greyscale ultrasound and SWE, and 32% of benign lesions were BI-RADS 3 and soft on SWE; lesions that are benign on both ultrasound and SWE may not require percutaneous biopsy or short-term follow-up.
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Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Técnicas de Imagem por Elasticidade/métodos , Palpação , Ultrassonografia Mamária/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Diagnóstico Diferencial , Feminino , Humanos , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Método Simples-Cego , Adulto JovemRESUMO
RATIONALE AND OBJECTIVES: To investigate if anisotropy at two-dimensional shear wave elastography (SWE) suggests malignancy and whether it correlates with prognostic and predictive factors in breast cancer. MATERIALS AND METHODS: Study group A of 244 solid breast lesions was imaged with SWE between April 2013 and May 2014. Each lesion was imaged in radial and in antiradial planes, and the maximum elasticity, mean elasticity, and standard deviation were recorded and correlated with benign/malignant status, and if malignant, correlated with conventional predictive and prognostic factors. The results were compared to a study group B of 968 solid breast lesions, which were imaged in sagittal and in axial planes between 2010 and 2013. RESULTS: Neither benign nor malignant lesion anisotropy is plane dependent. However, malignant lesions are more anisotropic than benign lesions (P ≤ 0.001). Anisotropy correlates with increasing elasticity parameters, breast imaging-reporting and data system categories, core biopsy result, and tumor grade. Large cancers are significantly more anisotropic than small cancers (P ≤ 0.001). The optimal anisotropy cutoff threshold for benign/malignant differentiation of 150 kPa(2) achieves the best sensitivity (74%) with a reasonable specificity (63%). CONCLUSIONS: Anisotropy may be useful during benign/malignant differentiation of solid breast masses using SWE. Anisotropy also correlates with some prognostic factors in breast cancer.
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Neoplasias da Mama/diagnóstico por imagem , Técnicas de Imagem por Elasticidade/métodos , Ultrassonografia Mamária/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anisotropia , Mama/patologia , Neoplasias da Mama/patologia , Diferenciação Celular , Feminino , Humanos , Pessoa de Meia-Idade , Prognóstico , Sensibilidade e Especificidade , Adulto JovemRESUMO
Shear wave elastography (SWE) shows promise as an adjunct to greyscale ultrasound examination in assessing breast masses. In breast cancer, higher lesion stiffness on SWE has been shown to be associated with features of poor prognosis. The purpose of this study was to assess whether lesion stiffness at SWE is an independent predictor of lymph node involvement. Patients with invasive breast cancer treated by primary surgery, who had undergone SWE examination were eligible. Data were retrospectively analysed from 396 consecutive patients. The mean stiffness values were obtained using the Aixplorer® ultrasound machine from SuperSonic Imagine Ltd. Measurements were taken from a region of interest positioned over the stiffest part of the abnormality. The average of the mean stiffness value obtained from each of two orthogonal image planes was used for analysis. Associations between lymph node involvement and mean lesion stiffness, invasive cancer size, histologic grade, tumour type, ER expression, HER-2 status and vascular invasion were assessed using univariate and multivariate logistic regression. At univariate analysis, invasive size, histologic grade, HER-2 status, vascular invasion, tumour type and mean stiffness were significantly associated with nodal involvement. Nodal involvement rates ranged from 7 % for tumours with mean stiffness <50 kPa to 41 % for tumours with a mean stiffness of >150 kPa. At multivariate analysis, invasive size, tumour type, vascular invasion, and mean stiffness maintained independent significance. Mean stiffness at SWE is an independent predictor of lymph node metastasis and thus can confer prognostic information additional to that provided by conventional preoperative tumour assessment and staging.
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Axila , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Técnicas de Imagem por Elasticidade , Linfonodos/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Gradação de Tumores , Prognóstico , Fatores de RiscoRESUMO
PURPOSE: To compare the histologic prognostic feature of invasive breast cancer with mean stiffness as measured with shear-wave elastography. MATERIALS AND METHODS: This retrospective study was exempted from ethical committee review. Patient consent for use of images for research was obtained. The study group comprised 101 consecutive women (age range, 38-91 years) with solid lesions identified during routine breast ultrasonography (US) performed between April 2010 and March 2011 and subsequently confirmed at histologic examination to be invasive cancers. Four elastographic images in two orthogonal planes were obtained of each lesion, and mean stiffness values were obtained from each image. Histologic findings following surgery were used for comparison, namely histologic grade, tumor type, invasive size, vascular invasion status, and lymph node status. Relationship between mean stiffness and histologic parameters was investigated by using a general linear model and multiple regression analysis. RESULTS: High histologic grade (P < .0001), large invasive size (P < .0001), lymph node involvement (P < .0001), tumor type (P < .0001), and vascular invasion (P = .0077) all showed statistically significant positive association with high mean stiffness values. Multiple linear regression indicated that invasive size is the strongest pathologic determinant of mean stiffness (P < .0001), with histologic grade also having significant influence (P = .022). CONCLUSION: In this study, breast cancers with higher mean stiffness values at shear-wave elastography had poorer prognostic features.
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Neoplasias da Mama/diagnóstico por imagem , Técnicas de Imagem por Elasticidade/métodos , Invasividade Neoplásica/diagnóstico por imagem , Ultrassonografia Mamária/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia por Agulha , Neoplasias da Mama/patologia , Diagnóstico Diferencial , Feminino , Humanos , Modelos Lineares , Metástase Linfática , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Estudos RetrospectivosRESUMO
INTRODUCTION: Shear wave elastography is a new method of obtaining quantitative tissue elasticity data during breast ultrasound examinations. The aims of this study were (1) to determine the reproducibility of shear wave elastography (2) to correlate the elasticity values of a series of solid breast masses with histological findings and (3) to compare shear wave elastography with greyscale ultrasound for benign/malignant classification. METHODS: Using the Aixplorer® ultrasound system (SuperSonic Imagine, Aix en Provence, France), 53 solid breast lesions were identified in 52 consecutive patients. Two orthogonal elastography images were obtained of each lesion. Observers noted the mean elasticity values in regions of interest (ROI) placed over the stiffest areas on the two elastography images and a mean value was calculated for each lesion. A sub-set of 15 patients had two elastography images obtained by an additional operator. Reproducibility of observations was assessed between (1) two observers analysing the same pair of images and (2) findings from two pairs of images of the same lesion taken by two different operators. All lesions were subjected to percutaneous biopsy. Elastography measurements were correlated with histology results. After preliminary experience with 10 patients a mean elasticity cut off value of 50 kilopascals (kPa) was selected for benign/malignant differentiation. Greyscale images were classified according to the American College of Radiology (ACR) Breast Imaging Reporting and Data System (BI-RADS). BI-RADS categories 1-3 were taken as benign while BI-RADS categories 4 and 5 were classified as malignant. RESULTS: Twenty-three benign lesions and 30 cancers were diagnosed on histology. Measurement of mean elasticity yielded an intraclass correlation coefficient of 0.99 for two observers assessing the same pairs of elastography images. Analysis of images taken by two independent operators gave an intraclass correlation coefficient of 0.80. Shear wave elastography versus greyscale BI-RADS performance figures were sensitivity: 97% vs 87%, specificity: 83% vs 78%, positive predictive value (PPV): 88% vs 84%, negative predictive value (NPV): 95% vs 82% and accuracy: 91% vs 83% respectively. These differences were not statistically significant. CONCLUSIONS: Shear wave elastography gives quantitative and reproducible information on solid breast lesions with diagnostic accuracy at least as good as greyscale ultrasound with BI-RADS classification.