Virtual Touch IQ elastography reduces unnecessary breast biopsies by applying quantitative “rule-in” and “rule-out” threshold values

Abstract

Our purpose was to evaluate Virtual Touch IQ (VTIQ) elastography and identify quantitative “rule-in” and “rule-out” thresholds for the probability of malignancy, which can help avoid unnecessary breast biopsies. 189 patients with 196 sonographically evident lesions were included in this retrospective, IRB-approved study. Quantitative VTIQ images of each lesion measuring the respective maximum Shear Wave Velocity (SWV) were obtained. Paired and unpaired, non-parametric statistics were applied for comparisons as appropriate. ROC-curve analysis was used to analyse the diagnostic performance of VTIQ and to specify “rule-in” and “rule-out” thresholds for the probability of malignancy. The standard of reference was either histopathology or follow-up stability for >24 months. 84 lesions were malignant and 112 benign. Median SWV of benign lesions was significantly lower than that of malignant lesions (p < 0.001). The application of a “rule-out” threshold of 1.9 m/s lead to a sensitivity of >98% with a concomitant significant (p = 0.032) reduction in false positive cases of almost 15%, whereas a “rule-in” threshold of 6.5 m/s suggested a probability of malignancy of >95%. In conclusion, VTIQ elastography accurately differentiates malignant from benign breast lesions. The application of quantitative “rule-in” and “rule-out” thresholds is feasible and allows reduction of unnecessary benign breast biopsies by almost 15%.

Microstructural breast tissue characterization: A head-to-head comparison of Diffusion Weighted Imaging and Acoustic Radiation Force Impulse elastography with clinical implications

“…It is performed during the US examination and leads to an increase of the specificity of B-mode US. Thus, it also has the potential to significantly reduce the number of unnecessary biopsy recommendations caused by false-positive B-mode results [35][36][37]. In our study, using a threshold of 2.33 m/s could correctly classify more than 40% of biopsied benign lesions as such, rendering their histologic work-up unnecessary.…”

Implementation of machine learning into clinical breast MRI: Potential for objective and accurate decision-making in suspicious breast masses

“…Such decision rules have been described as promising tools for breast MRI assessment [7,29], enabling exact diagnostic statements of either presence (rule-in) or absence of malignancy (rule-out). As a common principle, if sensitivity is high, a "negative" test result will rule out malignancy, and with a high specificity, a "positive" test result will rule in malignancy [30][31][32]. Thus, rule-in and rule-out criteria were defined as follows:…”

The Potential of Shear Wave Elastography to Reduce Unnecessary Biopsies in Breast Cancer Diagnosis: An International, Diagnostic, Multicenter Trial

“…The choice of the prespecified cutoff at 3.5 m/s was based on our previous pilot trials in this field [4][5][6]11]. The effect of other SWE cutoffs was descriptively evaluated in exploratory analyses.…”

“…Recently, shear wave elastography (SWE), a specific ultrasound technique to quantify the stiffness of a lesion on imaging, showed promising results to reduce the number of unnecessary biopsies in some pilot trials [4][5][6][7][8][9][10][11] and one prospective multicenter trial [12]. SWE quantifies the stiffness of a lesion by evaluating the propagating speed of shear waves through the tissuethe output measurement is given either in meters per second (m/s) or kilopascals [13].…”