Accuracy of Tumor Sizing in Breast Cancer: A Comparison of Strain Elastography, 3-D Ultrasound and Conventional B-Mode Ultrasound with and without Compound Imaging

Accuracy of conventional ultrasound, contrast-enhanced ultrasound and dynamic contrast-enhanced magnetic resonance imaging in assessing the size of breast cancer

OBJECTIVE

This study was performed to investigate the accuracy of conventional ultrasound (US), contrast-enhanced US (CEUS), and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing the size of breast cancer.

METHODS

In total, 49 breast cancer lesions of 48 patients were included in this study. The inclusion criteria were the performance of total mastectomy or breast-conserving surgery for treatment of breast cancer in our hospital from January 2017 to December 2020 with complete pathological results, as well as the performance of conventional US, CEUS, and DCE-MRI examinations with complete results. The exclusion criteria were non-mass breast cancer shown on conventional US or DCE-MRI, including that found on CEUS with no boundary with surrounding tissues and no confirmed tumor scope; a tumor too large to be completely displayed in the US section, thus affecting the measurement results; the presence of two nodules in the same breast that were too close to each other to be distinguished by any of the three imaging methods; and treatment with preoperative chemotherapy. Preoperative conventional US, CEUS, and DCE-MRI examinations were performed. The postoperative pathological results were taken as the gold standard. The lesion size was represented by its maximum diameter. The accuracy, overestimation, and underestimation rates of conventional US, CEUS, and DCE-MRI were compared.

RESULTS

The maximum lesion diameter on US, CEUS, DCE-MRI and pathology were 1.62±0.63 cm (range, 0.6-3.5 cm), 2.05±0.75 cm (range, 1.0-4.0 cm), 1.99±0.74 cm (range, 0.7-4.2 cm) and 1.92±0.83 cm (range, 0.5-4.0 cm), respectively. The lesion size on US was significantly smaller than that of postoperative pathological tissue (P <  0.05). However, there was no significant difference between the CEUS or DCE-MRI results and the pathological results. The underestimation rate of conventional US (55.1%, 27/49) was significantly higher than that of CEUS (20.4%, 10/49) and DCE-MRI (24.5%, 12/49) (P <  0.001 and P = 0.002, respectively). There was no significant difference in the accuracy of CEUS (36.7%, 18/49) and DCE-MRI (34.7%, 17/49) compared with conventional US (26.5%, 13/49); however, the accuracy of both groups tended to be higher than that of conventional US. The overestimation rate of CEUS (42.9%, 21/49) and DCE-MRI (40.8%, 20/49) was significantly higher than that of conventional US (18.4%, 9/49) (P = 0.001 and P = 0.015, respectively).

CONCLUSIONS

CEUS and DCE-MRI show similar performance when evaluating the size of breast cancer. However, CEUS is more convenient, has a shorter operation time, and has fewer restrictions on its use. Notably, conventional US is more prone to underestimate the size of lesions, whereas CEUS and DCE-MRI are more prone to overestimate the size.

Utility of Ultrasound Strain Elastography to Differentiate Benign from Malignant Lesions of the Breast

Background

The purpose of this study was to determine the utility and diagnostic performance of strain elastography (SE) in differentiating benign from malignant lesions of the breast.

Methods

In this prospective study, 50 palpable breast masses in 50 patients were examined by mammography, B-mode ultrasound (US) and SE. Lesions were categorized using Breast Imaging Reporting and Data System (BIRADS) scoring based on mammographic and sonographic features. Elasticity scores were assessed on a five-point scale based on the distribution of strain, and the lesion size on SE imaging and B-mode (elasticity imaging/B mode [EI/B] ratio) was compared. Findings were correlated with the BIRADS assessment and diagnostic performance of sonoelastography was evaluated taking histopathology as reference standard.

Results

Histopathology revealed 29 (58%) malignant and 21 (42%) benign lesions. Infiltrative ductal carcinoma and fibroadenoma were the most common malignant and benign lesions, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of SE was 100%, 76.1%, 85.2%, 100%, and 90%, respectively. Higher elasticity score was significantly associated with malignant histopathology (P < 0.00001). The mean EI/B ratio for malignant lesions was 1.36 ± 0.24 while that of benign lesions was 1.03 ± 0.30 (P = 0.000).

Conclusion

Real-time SE of the breast, with its superior sensitivity and specificity, could provide improved characterization of benign and malignant breast masses compared with mammography and conventional US. Due to greater diagnostic accuracy, SE can be an effective adjunctive tool to B-mode US in predicting malignancy of breast, as well as in reducing the need for biopsies in benign breast lesions.

Accuracy of tumor size measurement: comparison of B-mode ultrasound, strain elastography, and 2D and 3D shear wave elastography with histopathological lesion size

BACKGROUND

Predicting the exact extent of a breast tumor is of great importance for oncologic treatment strategies. Different types of elastography can be used as new tools for measuring lesion size.

PURPOSE

To provide evidence regarding the accuracy of tumor size measurement of strain elastography (SE), two-dimensional (2D) and three-dimensional (3D) shear wave elastography (SWE), and conventional B-image ultrasound.

MATERIAL AND METHODS

In this prospective study, the diameter of 105 malignant breast lesions was measured by SE, 2D and 3D SWE, and B-mode ultrasound. The histopathological lesion size was compared to all imaging-based measuring methods.

RESULTS

The mean lesion size of all breast carcinomas was 1.54 cm. B-mode ultrasound underestimates breast cancer size in 65.7 % of all cases in this study ( P < 0.0001). Mean lesion size was more accurately determined by SE, 2D and 3D SWE compared to B-mode ultrasound. Absolute differences between measured and actual lesion are smaller for B-mode ultrasound (0.26 cm) than for SE (0.41 cm) and 2D and 3D SWE (0.41 cm and 0.44 cm, respectively).

CONCLUSION

B-mode ultrasound allows more accurate lesion size measurement than SE and 2D or 3D SWE but has a significantly higher risk of underestimating tumor size which could lead to incomplete margins during surgery. 3D SWE was not superior to 2D SWE or SE but by trend more precise in predicting the size of invasive lobular carcinoma.