Diagnostic Performance of Quantitative and Qualitative Elastography for Axillary Lymph Node Metastasis in Breast Cancer: A Systematic Review and Meta-Analysis

Shear wave elastography versus strain elastography to identify benign superficial lymph nodes: sonographic assessment with histopathological confirmation

Background

Differentiation between benign and malignant superficial lymph nodes (LNs) presents clinical dilemma. No specific criteria are established with conventional ultrasound to make a distinction. We aimed to study the added value of shear wave velocity (SWV) measurement with acoustic radiation force impulse (ARFI) and strain elastography (SE) to identify benign superficial LNs. The study included 115 superficial LNs subjected to conventional ultrasonography, 4-scale strain elastography and shear wave velocity measurement using ARFI. Histopathological analysis was obtained for all examined nodes.

Results

SE correctly diagnosed 89.3% of the reactive and 92.2% of the metastatic LNs and erroneously diagnosed 72.7% of the lymphoma LNs as being benign. Overall sensitivity, specificity, PPV, NPV and accuracy were 74.4%, 73%, 85.3%, 57.4% and 73.9%, respectively. The receiver operating curve analysis of SWV measurement using ARFI revealed a cut-off value of ≥ 2.70 m/sec to recognize malignant LNs and to obtain best sensitivity (88.5%) and specificity (89.2%) (Area under the curve: 0.819, 95% confidence interval (CI): 0.744 and 0.894). The PPV, NPV and accuracy were 94.5%, 78.6% and 88.7%, respectively. As compared to SE, ARFI boosted the diagnostic accuracy of lymphoma LNs from 27.3 to 68.2% and showed better specificity and NPV to identify benign LN as contrasted to SE.

Conclusions

SE could be adequate to differentiate reactive from metastatic LN but not from Lymphomas. Shear wave elastography is a reasonable imaging modality to identify benign lymph nodes. ARFI at a cut-off value of < 2.7 m/sec was superior to SE and the best B-mode features.

Diagnostic Efficacy of Ultrasonography, Doppler Ultrasonography and Elastography in the Evaluation of Suspected Malignant Lymph Nodes

Aim

In this prospective study, the efficiency of imaging findings was investigated by comparing the histopathological results of lymph nodes with Doppler and ultrasound features and elasticity scores.

Material and method

A total of 100 cervical or axillary lymph nodes with a suspected malignancy or whose size did not decrease after treatment were examined. In addition to the demographic data of the patients, B-mode ultrasound, Doppler ultrasound, and elastography features of the lymph nodes were evaluated prospectively. The irregular shape, increased size, pronounced hypoechogenicity, presence of micro/macro calcification, short axis/long axis ratio >2, increased size of the short axis, increased cortex thickness, obliterated hilus or increased cortex thickness >3.5 mm were evaluated on ultrasound. Resistivity index, pulsatility index, acceleration rate and time were evaluated for intranodal arterial structures on color. Doppler ultrasound, strain ratio value and elasticity score were recorded on ultrasound elastography. After sonographic examination, patients underwent ultrasound-guided fine needle aspiration cytology or tru-cutting needle biopsy. Histopathological examination results of the patients were compared with the B-mode ultrasound, Doppler ultrasound, and ultrasound elastography.

Results

When the individual and combined effects of the ultrasound, Doppler ultrasound, and ultrasound elastography were evaluated, the combination of all three imaging methods was found to have the highest sensitivity and the highest overall accuracy (90.4% and 73.9%). As an individual method Doppler ultrasound had the highest specificity (77.8%). B-mode ultrasound was found to have the lowest accuracy (56.7%) both in individual and combined evaluations.

Conclusion

Addition of ultrasound elastography to the combination of B-mode and Doppler ultrasound findings increases diagnostic sensitivity and accuracy in the differentiation of benign and malignant lymph nodes.

Evaluating Different Quantitative Shear Wave Parameters of Ultrasound Elastography in the Diagnosis of Lymph Node Malignancies: A Systematic Review and Meta-Analysis

Shear wave elastography (SWE) has shown promise in distinguishing lymph node malignancies. However, the diagnostic accuracies of various SWE parameters that quantify tissue stiffness are yet to be demonstrated. To evaluate the pooled diagnostic accuracy of different SWE parameters for differentiating lymph node malignancies, we conducted a systematic screening of four databases using the PRISMA guidelines. Lymph node biopsy was adopted as the reference standard. E_max (maximum stiffness), E_mean (mean stiffness), E_min (minimum stiffness), and E_sd (standard deviation) SWE parameters were subjected to separate meta-analyses. A sub-group analysis comparing the use of E_max in cervical (including thyroid) and axillary lymph node malignancies was also conducted. Sixteen studies were included in this meta-analysis. E_max and E_sd demonstrated the highest pooled sensitivity (0.78 (95% CI: 0.69-0.87); 0.78 (95% CI: 0.68-0.87)), while E_mean demonstrated the highest pooled specificity (0.93 (95% CI: 0.88-0.98)). From the sub-group analysis, the diagnostic performance did not differ significantly in cervical and axillary LN malignancies. In conclusion, SWE is a promising adjunct imaging technique to conventional ultrasonography in the diagnosis of lymph node malignancy. SWE parameters of E_max and E_sd have been identified as better choices of parameters for screening clinical purposes.

Different Imaging Modalities for the Diagnosis of Axillary Lymph Node Metastases in Breast Cancer: A Systematic Review and Network Meta-Analysis of Diagnostic Test Accuracy

BACKGROUND

Accurate diagnosis of axillary lymph node metastasis (ALNM) of breast cancer patients is important to guide local and systemic treatment.

PURPOSE

To evaluate the diagnostic performance of different imaging modalities for ALNM in patients with breast cancer.

STUDY TYPE

Systematic review and network meta-analysis (NMA).

SUBJECTS

Sixty-one original articles with 8011 participants.

FIELD STRENGTH

1.5 T and 3.0 T.

ASSESSMENT

We used the QUADAS-2 and QUADAS-C tools to assess the risk of bias in eligible studies. The identified articles assessed ultrasonography (US), MRI, mammography, ultrasound elastography (UE), PET, CT, PET/CT, scintimammography, and PET/MRI.

STATISTICAL ANALYSIS

We used random-effects conventional meta-analyses and Bayesian network meta-analyses for data analyses. We used sensitivity and specificity, relative sensitivity and specificity, superiority index, and summary receiver operating characteristic curve (SROC) analysis to compare the diagnostic value of different imaging modalities.

RESULTS

Sixty-one studies evaluated nine imaging modalities. At patient level, sensitivities of the nine imaging modalities ranged from 0.27 to 0.84 and specificities ranged from 0.84 to 0.95. Patient-based NMA showed that UE had the highest superiority index (5.95) with the highest relative sensitivity of 1.13 (95% confidence interval [CI]: 0.93-1.29) among all imaging methods when compared to US. At lymph node level, MRI had the highest superiority index (6.91) with highest relative sensitivity of 1.13 (95% CI: 1.01-1.23) and highest relative specificity of 1.11 (95% CI: 0.95-1.23) among all imaging methods when compared to US. SROCs also showed that UE and MRI had the largest area under the curve (AUC) at patient level and lymph node level of 0.92 and 0.94, respectively.

DATA CONCLUSION

UE and MRI may be superior to other imaging modalities in the diagnosis of ALNM in breast cancer patients at the patient level and the lymph node level, respectively. Further studies are needed to provide high-quality evidence to validate our findings.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 2.

Role of shear wave elastography as an adjunct to axillary ultrasonography in predicting nodal metastasis in breast cancer patients with suspicious nodes

Objective:

To evaluate the role of shear wave elastography (SWE) of suspicious axillary lymph nodes and its combination with B-mode USG in predicting nodal metastasis in breast cancer patients.

Methods:

Prospective observational study was performed from June 2018 to August 2020 on breast cancer patients with suspicious axillary nodes on USG. B-mode features (cortical thickness, effacement of fatty hilum, non-hilar blood flow and round shape) and SWE parameters (Emax, Emin, Emean and ESD) of the node with the thickest cortex were evaluated. Diagnostic performances of USG, SWE and their combination were estimated using pathological status of the node on biopsy as the gold standard.

Results:

Of the 54 patients evaluated, optimal elasticity maps were obtained in 49 nodes of 49 patients (mean age, 46.3 ± 12.1 years; 48/49 (98%) females). On biopsy, 38 nodes (77.6%) had metastasis, while 11 (22.4%) had reactive hyperplasia. Emax, Emin, Emean and ESD of both cortex and hilum were significantly higher in metastatic than reactive nodes. Emax (cortex) ≥14.9 kPa had the best diagnostic performance (sensitivity, 73.7%; specificity, 81.8%). Cortical thickness ≥6.7 mm had the best diagnostic performance among B-mode features (sensitivity, 89.5%; specificity, 72.7%). Combining cortical thickness with effacement of fatty hilum and/or non-hilar blood flow yielded sensitivity of 89.5% and specificity of 90.9%. Addition of Emax (cortex) to cortical thickness and combination of ≥2 B-mode features increased their specificities to 90.9 and 100%, respectively.

Conclusions:

Metastatic axillary nodes are stiffer than reactive nodes on SWE in breast cancer patients. Emax (cortex) has the best diagnostic performance in differentiating between reactive hyperplasia and nodal metastasis. Combination of Emax (cortex) and cortical thickness increases the specificity for diagnosing metastasis, especially in nodes showing only cortical thickening.

Advances in knowledge:

Combination of SWE and B-mode USG is highly specific for differentiating metastasis from reactive hyperplasia in suspicious nodes of breast carcinoma patients, especially in nodes with only cortical thickening.

Diagnostic value of endobronchial ultrasound elastography combined with rapid onsite cytological evaluation in endobronchial ultrasound-guided transbronchial needle aspiration

Background

Endobronchial ultrasound (EBUS) elastography has been used in EBUS-guided transbronchial needle aspiration (EBUS-TBNA) to identify malignant lymph nodes based on tissue stiffness. Rapid onsite cytological evaluation (ROSE) has been widely utilized for onsite evaluation of sample adequacy and for guiding sampling during EBUS-TBNA. The aim of this study was to investigate the diagnostic value of combined EBUS elastography and ROSE in evaluating mediastinal and hilar lymph node status.

Methods

Retrospective chart review was performed from December 2018 to September 2020. Patient demographics, EBUS elastography scores, and ROSE, pathologic, and clinical outcome data were collected. The EBUS elastography scores were classified as follows: Type 1, predominantly nonblue; Type 2, partially blue and partially nonblue; and Type 3, predominantly blue. A receiver operating characteristic curve was used to compare the sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio for evaluation of malignant lymph nodes among the EBUS elastography, ROSE, and EBUS combined with ROSE groups.

Results

A total of 245 patients (345 lymph nodes) were included. The sensitivity and specificity of the EBUS elastography group for the diagnosis of malignant lymph nodes were 90.51% and 57.26%, respectively. The sensitivity and specificity in the ROSE group were 96.32% and 79.05%, respectively. The sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of EBUS elastography combined with ROSE were 86.61%, 92.65%, 11.78, and 0.14, respectively, and the area under the curve was 0.942.

Conclusions

Combining EBUS elastography and ROSE significantly increased the diagnostic value of EBUS-TBNA in evaluating mediastinal and hilar lymph node status compared to each method alone.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01748-4.

Diagnostic performance of quantitative and qualitative elastography for the differentiation of benign and malignant cervical lymph nodes: A protocol for systematic review and meta-analysis

BACKGROUND

Studies have shown inconsistent results regarding the diagnostic performance of quantitative and qualitative elastography for the differentiation of benign and malignant cervical lymph nodes. This meta-analysis aimed to estimate the diagnostic performance of ultrasound elastography in patients with cervical lymphadenopathy.

METHODS

We will search PubMed, Web of Science, Cochrane Library, and Chinese biomedical databases from their inceptions to the May 30, 2021, without language restrictions. Two authors will independently carry out searching literature records, scanning titles and abstracts, full texts, collecting data, and assessing risk of bias. Review Manager 5.2 and Stata14.0 software will be used for data analysis.

RESULTS

This systematic review will determine the accuracy of shear wave elastography and strain elastography in the differential diagnosis between benign and malignant cervical lymph nodes.

CONCLUSION

Its findings will provide helpful evidence for the accuracy of shear wave elastography and strain elastography in the differential diagnosis between benign and malignant cervical lymph nodes.

SYSTEMATIC REVIEW REGISTRATION

INPLASY202150109.

Diagnostic performance of elastography for breast non-mass lesions: A systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis aimed to evaluate the diagnostic performance of ultrasound elastography in the differentiation of benign and malignant breast non-mass lesions (NMLs).

METHODS

PubMed, Cochrane Library, and Embase databases were searched for eligible studies up to end of June 2021. The diagnostic performance of elastography for NMLs was investigated using pooled sensitivity and specificity, likelihood ratio, diagnostic odds ratio (DOR), post-test probability, and the area under hierarchical summary receiver operating characteristic curve (HSROC).

RESULTS

Eleven studies involving 812 NMLs (malignant 414) were included. The pooled sensitivity, specificity, DOR, positive likelihood ratio, and negative likelihood of elastography for the differentiation of benign and malignant breast NMLs were 79% (95 %CI: 71-85), 86% (95 %CI: 79-91), 23.32 (95 %CI: 13.38-40.66), 5.67 (95 %CI: 3.79-8.47), and 0.24 (95 %CI: 0.17-0.34), respectively. No significant publication bias existed. The area under the HSROC curve was 90% (95 %CI: 87-92). Fagan plots demonstrated good clinical utility. However, substantial heterogeneity existed. Country, measurement index, and number of lesions served as potential sources of heterogeneity.

CONCLUSIONS

The results of this study suggest that elastography has high diagnostic accuracy in differentiating between malignant and benign NMLs. Elastography can be a feasible and non-invasive tool for breast NMLs.

Clinical Value of Three Combined Ultrasonography Modalities in Predicting the Risk of Metastasis to Axillary Lymph Nodes in Breast Invasive Ductal Carcinoma

Objective

The present study aimed to assess the clinical value of conventional ultrasound (C-US), ultrasound elastography (UE), percutaneous contrast-enhanced ultrasound (P-CUES), and the combination of these three ultrasonography modalities for evaluating the risk of axillary lymph node (ALN) metastasis in breast invasive ductal carcinoma (IDC).

Methods

This retrospective analysis included 120 patients with pathologically confirmed IDC who underwent sentinel lymph node biopsy (SLNB) or axillary lymph node dissection (ALND). Based on the gold standard of postoperative pathology, ALN pathology results were evaluated and compared with findings obtained using C-US, UE, P-CUES, and the three modalities combined.

Results

(1) There was a statistically significant difference between the histological grade of the tumor and the pathological condition of ALNs. (2) The difference between C-US parameters and UE score were statistically significant. The accuracy of P-CEUS localization of SLNs was 100% (96/96) when compared with localization guided by methylene blue. The difference in the distribution of the four SLN enhancement patterns was statistically significant. (3) The sensitivity, specificity, positive predictive value, and negative predictive value of C-US and UE were 75%, 71%, 58%, and 89%, and 71%, 72%, 50%, and 86%, respectively. The sensitivity, specificity, positive predictive value, and negative predictive value of P-CUES were 91%, 82%, 78%, 92%, respectively. When all three modalities were combined, the sensitivity, specificity, positive predictive value, and negative predictive value were 94%, 89%, 86%, and 95%, respectively. In the detection of ALN metastasis, there was a good correlation between histopathological results and evaluations based on the three combined ultrasonography modalities (kappa: 0.82, p<0.001).

Conclusions

When compared to C-US, UE, or P-CEUS alone, the combination of the three ultrasonography modalities was found to be superior in distinguishing metastatic and non-metastatic ALNs. This combined strategy may aid physicians in determining the most appropriate approach to ALN surgery as well as the prognosis of breast IDC.

Ultrasound Elastography for the Evaluation of Lymph Nodes

The differential diagnosis of lymphadenopathy is important for predicting prognosis, staging, and monitoring the treatment, especially for cancer patients. Conventional computed tomography and magnetic resonance imaging characterize lymph node (LN) with disappointing sensitivity and specificity. Conventional ultrasound with the advantage of high resolution has been widely used for the LN evaluation. Ultrasound elastography (UE) using color map or shear wave velocity can non-invasively demonstrate the stiffness and homogeneity of both the cortex and medulla of LNs and can detect early circumscribed malignant infiltration. There is a need of a review to comprehensively discuss the current knowledge of the applications of various UE techniques in the evaluation of LNs. In this review, we discussed the principles of strain elastography and shear wave-based elastography, and their advantages and limitations in the evaluation of LNs. In addition, we comprehensively introduced the applications of various UE techniques in the differential diagnosis of reactive LNs, lymphoma, metastatic LNs, and other lymphadenopathy. Moreover, the applications of endoscopic UE and endobronchial UE are also discussed, including their use for improving the positive rate of diagnosis of fine-needle aspiration biopsy.