Quantitative assessment of the lipiodol staining after transarterial chemoembolization for hepatocellular carcinoma: can it predict tumor recurrence?

Background The degree of intratumoral lipiodol staining after conventional transarterial chemoembolization (cTACE) has the potential to predict tumor responses and disease prognosis. This study is aimed at evaluating the correlation between the lipiodol retention of the tumor with a complete response after cTACE and tumor recurrence by quantitative assessment. Methods From January 2013 to September 2023, every patient receiving cTACE for HCC was recognized. Inclusion criteria were patients with ≤6 HCCs and sizes 1-6 cm, with at least one tumor obtaining a complete response after cTACE, and available baseline and follow-up CT studies. Tumoral, cTACE procedural, and lipiodol staining parameters were analyzed. Using univariate and multivariate analysis, significant factors associated with tumor recurrence were identified. ROC curve analysis was used to identify the optimal cutoff point for the statistically significant factors, predicting tumor recurrence. Results The final population included 39 patients with 63 HCCs. Tumor recurrence was detected in 18/63 (28.6%) at a mean of 27.8 months. On univariate analysis, the incidence of tumor recurrence significantly increased with increased tumor size (p = 0.007), an inhomogeneous lipiodol staining pattern (p<0.001), a low minimum lipiodol radiodensity (p = 0.012), and a high lipiodol washout rate (p = 0.046). On multivariate analysis, an inhomogeneous lipiodol staining pattern (p<0.001) and a high lipiodol washout rate (p = 0.012) were significant predictors for tumor recurrence. On ROC analysis, a lipiodol washout rate of greater than 6.44 HU/month was related to tumor recurrence (sensitivity 83%, specificity 51%). Conclusions Inhomogeneous lipiodol staining pattern and lipiodol washout rate of >6.44 HU/month were predictors for recurrence of HCC after a complete response after cTACE. These correlations may provide useful guidance for subsequent imaging surveillance and treatment approaches.