The value of contrast-enhanced ultrasound quantitative parameters in the prognosis prediction of hepatocellular carcinoma after thermal ablation: a retrospective cohort study

Abstract

Background: The postoperative recurrence rate is the main factor affecting the prognosis of hepatocellular carcinoma (HCC) patients, this study sought to investigate the value of contrast-enhanced ultrasound (CEUS) quantitative parameters in predicting the recurrence and the survival of HCC patients after thermal ablation.

Methods: The data of 97 patients with pathologically diagnosed HCC who underwent thermal ablation were retrospectively included in this study. The patients had an average age of 46.6 years (range, 23-79 years), and 79 were male and 18 were female. CEUS follow-up was performed at 1- and 3-month after thermal ablation, then at 6-month intervals thereafter for 5 years. CEUS was performed before thermal ablation, and the results were analyzed quantitatively using CEUS perfusion software (VueBox^®, Bracco, Italy). The ratios of the CEUS quantitative parameters between the HCC lesions and reference liver parenchyma were calculated. The parameters included the average contrast signal intensity (MeanLin), peak enhancement (PE), rising time (RT), fall time (FT), time to peak (TTP), mean transit time (mTT), perfusion index (PI), Wash-in Area Under the Curve (WiAUC), Wash-in Rate (WiR), Wash-in Perfusion Index (WiPI), Wash-out Area Under the Curve (WoAUC), Wash-out Rate (WoR), and WiAUC + WoAUC (WiWoAUC). The correlations between the preoperative CEUS quantitative parameter ratios, the blood laboratory indexes, postoperative recurrence, and survival were analyzed using log-rank tests and a Cox regression model.

Results: The average follow-up duration period was 79 months (range, 5-145 months). The average recurrence time after ablation was 1-127 months, and the median disease-free survival time was 21 months. The 1-, 3- and 5-year survival rates were 96.9%, 92.3%, and 80.6%, respectively. The log-rank tests showed that tumor size, prothrombin time, and WiAUC, WoAUC, and WiWoAUC ratios were predictors of survival, and aspartate aminotransferase was a predictor of recurrence. The Cox regression analysis showed that tumor size [odds ratio (OR): 6.421; 95% CI: 1.434-28.761] and alanine transaminase (OR: 0.88; 95% CI: 0.010-0.742) were predictors of a poor prognosis.

Conclusions: CEUS quantitative parameters before thermal ablation and blood laboratory indexes provide potential clinical value for predicting the postoperative recurrence and survival of HCC patients.

Keywords: Contrast-enhanced ultrasound (CEUS); ablation; hepatocellular carcinoma (HCC); prognosis.

Figure 1

Flow chart for participant inclusion.

Figure 2

Representative VueBox^® analysis results of CEUS images and time-intensity curves for HCC. The ROIs were drawn for the quantitative analysis (Blue: Delimitation ROI; Green: lesion area; Yellow: normal reference area of liver parenchyma). CEUS, contrast-enhanced ultrasound; HCC, hepatocellular carcinoma; ROI, regions of interest.

Figure 3

Survival time and recurrence time of the 97 patients.

Figure 4

Survival curve for each survival factor (n=97). PT, prothrombin time; WiAUC, Wash-in Area Under the Curve; WoAUC, Wash-out Area Under the Curve; WiWoAUC, WiAUC + WoAUC; AST, aspartate aminotransferase.