Background and Aims
We assessed the imaging outcomes of Liver Imaging Reporting and Data System (LI‐RADS) v2018 categories in prospective hepatocellular carcinoma (HCC) surveillance cohort and determined imaging features significantly predictive of progression to a malignant LI‐RADS category.
Methods
The imaging outcomes of 120 patients (162 observations) prospectively enrolled between November 2011 and August 2012 were analysed according to LI‐RADS v2018. Cumulative incidences for progression to a malignant category (LR‐5 or LR‐M) and LR‐4 or higher were calculated for each baseline category and compared using log‐rank tests. Clinical variables and imaging features significantly predictive of progression to a malignant category were evaluated using Cox proportional hazards modelling.
Results
The 162 observations were initially categorized into 60 LR‐2, 75 LR‐3 and 27 LR‐4. For LR‐4 observations, the 1‐year, 3‐year and 5‐year cumulative incidences of progression to a malignant category were 18.5% (95% confidence interval, 6.6–35.2%), 43.0% (23.1–61.5%) and 52.5% (25.9–73.5%), which were significantly higher than those of LR‐2 and LR‐3 (p < .001). For LR‐3, the 1‐year, 3‐year and 5‐year cumulative incidences of progression to LR‐4 or higher were 4.1% (1.1–10.4%), 13.9% (6.7–23.6%) and 23.1% (12.7–35.4%), which were significantly higher than that of LR‐2 (p = .009). In multivariable analysis, size ≥1.0 cm (hazard ratio [HR] = 2.58, 1.04–6.40) and nonrim arterial‐phase hyperenhancement (HR = 2.45, 1.11–5.42) were significantly independently associated with progression to a malignant category.
Conclusion
Long‐term imaging outcomes differed significantly according to LI‐RADS category. Size ≥1.0 cm and nonrim arterial‐phase hyperenhancement were imaging features significantly predictive of progression to a malignant category.