Correlation between quantitative parameters of CEUS and Ki-67 labeling index in soft-tissue sarcoma

Abstract

Background Apart from the immunohistochemical Ki-67 labeling index (LI), clinicians need a non-invasive and convenient way to predict the prognosis of patients with soft-tissue sarcoma (STS). Purpose To investigate the correlation between quantitative parameters of contrast-enhanced ultrasound (CEUS) and Ki-67 LI in STS. Material and Methods A total of 25 patients diagnosed with STS who underwent CEUS examination using SonoVue®, between January 2019 to November 2020, were included in the study. They were then divided into a high-proliferation group and low-proliferation group according to 30% Ki-67 positive tumor cells. The quantitative parameters in the semi-automatic time intensity curve analysis software, including arrival time, time to peak, peak intensity, rise time (RT), rise slope, 50% wash-out time, and 50% wash-out intensity, were extracted from the time intensity curve of CEUS by two independent observers. Statistical evaluation of the correlation and difference between CEUS quantitative parameters and Ki-67 LI between the two groups was performed. According to the area under the curve (AUC) analysis, optimal cutoff points of parameters with significant difference were determined. Results CEUS RT of the high-proliferation group in STS was significantly higher than that of the low-proliferation group (ρ = 0.509, P = 0.01). The most reasonable cutoff to distinguish between low- and high-proliferation groups was 10.84 s. The sensitivity, specificity, and the AUC were 86.7%, 80%, and 0.80, respectively. Conclusion CEUS RT was correlated with Ki-67 LI of STS, which can be used as a minimally invasive auxiliary tool to predict the prognosis of STS in clinical practice.