# Time-Intensity Curve Analysis of Contrast-Enhanced Ultrasound for Non-Ossified Thyroid Cartilage Invasion in Laryngeal Squamous Cell Carcinoma

## TL;DR

This study shows that contrast-enhanced ultrasound can effectively detect thyroid cartilage invasion in laryngeal cancer by analyzing blood flow patterns.

## Contribution

The study introduces a novel use of CEUS time-intensity curve parameters to detect non-ossified thyroid cartilage invasion in laryngeal SCC.

## Key findings

- A ∆TTP cut-off of ≤ 8.9 s achieved 100% sensitivity and 76.9% specificity for detecting cartilage invasion.
- Combining ∆TTP and PI increased diagnostic accuracy to 96.8%.
- Visual assessment of CEUS had 83.3% sensitivity and 84.6% specificity for cartilage invasion.

## Abstract

Objective: This study aimed to assess the diagnostic value of contrast-enhanced ultrasound (CEUS) time–intensity curve (TIC) parameters in detecting non-ossified thyroid cartilage invasion in patients with laryngeal squamous cell carcinoma (SCC). Methods: A CEUS TIC analysis was performed on 32 cases from 27 patients with histologically confirmed laryngeal SCC. The diagnostic performance of time to peak (TTP), peak intensity (PI), wash-in slope (WIS), area under the curve (AUC), and their quantitative differences (∆TTP, ∆PI, ∆WIS, and ∆AUC) to discriminate between the invaded and the non-invaded non-ossified thyroid cartilage was determined using ROC analysis. A logistic regression analysis was employed to identify significant predictors. Results: In an ROC analysis, of all TIC parameters analyzed separately, ∆TTP showed the greatest diagnostic performance (AUC: 0.85). A ∆TTP cut-off of ≤ 8.9 s differentiated between the invaded and the non-invaded non-ossified thyroid cartilage with a sensitivity of 100%, specificity of 76.9%, and accuracy of 81.3%. A combination of ∆TTP and PI increased the AUC to 0.93, specificity to 100%, and accuracy to 96.8%, but reduced the sensitivity to 83.3%. Meanwhile, the visual assessment of enhancement on CEUS to detect cartilage invasion had 83.3% sensitivity and 84.6% specificity. In a univariate logistic regression, only ∆TTP was a significant predictor of non-ossified thyroid cartilage invasion (OR: 0.80; 95% CI: 0.64–1.00). For every second increase in ∆TTP, the probability of thyroid cartilage invasion decreased by 20%. Conclusions: CEUS TIC parameters, particularly a combination of ∆TTP and PI, showed high diagnostic performance in the detection of non-ossified thyroid cartilage invasion in laryngeal SCC.