The potential role of combined shear wave elastography and superb microvascular imaging for early prediction the pathological response to neoadjuvant chemotherapy in breast cancer

Ultrasound-based quantitative microvasculature imaging for early prediction of response to neoadjuvant chemotherapy in patients with breast cancer

BACKGROUND

Angiogenic activity of cancerous breast tumors can be impacted by neoadjuvant chemotherapy (NAC), thus potentially serving as a marker for response monitoring. While different imaging modalities can aid in evaluation of tumoral vascular changes, ultrasound-based approaches are particularly suitable for clinical use due to their availability and noninvasiveness. In this paper, we make use of quantitative high-definition microvasculature imaging (qHDMI) based on contrast-free ultrasound for assessment of NAC response in breast cancer patients.

METHODS

Patients with invasive breast cancer recommended treatment with NAC were included in the study and ultrafast ultrasound data were acquired at pre-NAC, mid-NAC, and post-NAC time points. Data acquisitions also took place at two additional timepoints - at two and four weeks after NAC initiation in a subset of patients. Ultrasound data frames were processed within the qHDMI framework to visualize the microvasculature in and around the breast tumors. Morphological analyses on the microvasculature structure were performed to obtain 12 qHDMI biomarkers. Pathology from surgery classified response using residual cancer burden (RCB) and was used to designate patients as responders (RCB 0/I) and non-responders (RCB II/III). Distributions of imaging biomarkers across the two groups were analyzed using Wilcoxon rank-sum test. The trajectories of biomarker values over time were investigated and linear mixed effects models were used to evaluate interactions between time and group for each biomarker.

RESULTS

Of the 53 patients included in the study, 32 (60%) were responders based on their RCB status. The results of linear mixed effects model analysis showed statistically significant interactions between group and time in six out of the 12 qHDMI biomarkers, indicating differences in trends of microvascular morphological features by responder status. In particular, vessel density (p-value: 0.023), maximum tortuosity (p-value: 0.049), maximum diameter (p-value: 0.002), fractal dimension (p-value: 0.002), mean Murray's deviation (p-value: 0.034), and maximum Murray's deviation (p-value: 0.022) exhibited significantly different trends based on responder status.

CONCLUSIONS

We observed microvasculature changes in response to NAC in breast cancer patients using qHDMI as an objective and quantitative contrast-free ultrasound framework. These finding suggest qHDMI may be effective in identifying early response to NAC.

Diagnostic value of mammography combined with ultrasound shear wave elastography and magnetic resonance imaging in breast cancer

Breast cancer is one of the most common malignancies affecting women worldwide, and an early diagnosis is critical for improving prognosis. The present study aimed to investigate the diagnostic value of mammography (MG) combined with ultrasound shear wave elastography (SWE) and magnetic resonance imaging (MRI) for the early screening of breast cancer. Patients with breast tumors who underwent lumpectomy at a single hospital between December 2021 and January 2023 were selected and categorized into a benign or malignant group based on pathological findings. All patients had undergone examinations with MG, SWE and MRI. Imaging parameters were subsequently compared between the two groups. A total of 93 patients with breast tumors were included in the study, comprising 37 individuals in the benign group and 56 in the malignant group. MG findings revealed that patients in the malignant group exhibited significantly higher incidences of high breast glandular density, irregular mass margins, unclear mass borders and axillary lymph node involvement compared with those in the benign group. SWE results indicated that the elasticity ratio of the lesion to fat, and the mean and maximum values of the elastic modulus were significantly lower in the benign group than in the malignant group. Additionally, MRI findings demonstrated that the MRI-measured maximum diameter was larger, and the prevalence of irregular lesion morphology, irregular mass margins, signal enhancement and type III time-signal intensity curves was greater in the malignant group compared with the benign group. The diagnostic sensitivity, specificity, positive predictive value and negative predictive value of MG + SWE + MRI were 94.6, 86.5, 91.4 and 91.4%, respectively. Furthermore, the diagnostic efficacy of this combination surpassed that of MG + SWE, MG + MRI and SWE + MRI (area under the curve, 0.906 vs. 0.767, 0.758 and 0.763, respectively). In conclusion, the combination of MG with SWE and MRI exhibits a superior performance in the early diagnosis of breast cancer, exhibiting higher diagnostic accuracy and reliability compared with pairwise combinations.

Elasticity Values as a Predictive Modality for Response to Neoadjuvant Chemotherapy in Breast Cancer

Shear-wave elastography (SWE) is an effective tool in discriminating malignant lesions of breast and axillary lymph node metastasis in patients with breast cancer. However, the association between the baseline elasticity value of breast cancer and the treatment response of neoadjuvant chemotherapy is yet to be elucidated. Baseline SWE measured mean stiffness (E-mean) and maximum stiffness (E-max) in 830 patients who underwent neoadjuvant chemotherapy and surgery from January 2012 to December 2022. Association of elasticity values with breast pCR (defined as ypTis/T0), pCR (defined as ypTis/T0, N0), and tumor-infiltrating lymphocytes (TILs) was analyzed. Of 830 patients, 356 (42.9%) achieved breast pCR, and 324 (39.0%) achieved pCR. The patients with low elasticity values had higher breast pCR and pCR rates than those with high elasticity values. A low E-mean (adjusted odds ratio (OR): 0.620; 95% confidence interval (CI): 0.437 to 0.878; p = 0.007) and low E-max (adjusted OR: 0.701; 95% CI: 0.494 to 0.996; p = 0.047) were independent predictive factors for breast pCR. Low elasticity values were significantly correlated with high TILs. Pretreatment elasticity values measured using SWE were significantly associated with treatment response and inversely correlated with TILs, particularly in HR+HER2- breast cancer and TNBC.