Hepatocellular carcinoma. CT texture analysis as a predictor of survival after surgical resection

To determine whether image texture parameters analysed on pre-operative contrast-enhanced computed tomography (CT) can predict overall survival and recurrence-free survival in patients with hepatocellular carcinoma (HCC) treated by surgical resection. We retrospectively included all patients operated for HCC who had liver contrast-enhanced CT within 3 months prior to treatment in our centre between 2010 and 2015. The following texture parameters were evaluated on late-arterial and portal-venous phases: mean grey-level, standard deviation, kurtosis, skewness and entropy. Measurements were made before and after spatial filtration at different anatomical scales (SSF) ranging from 2 (fine texture) to 6 (coarse texture). Lasso penalised Cox regression analyses were performed to identify independent predictors of overall survival and recurrence-free survival. Forty-seven patients were included. Median follow-up time was 345 days (interquartile range $[$IQR$]$, 176-569). Nineteen patients had a recurrence at a median time of 190 days (IQR, 141-274) and 13 died at a median time of 274 days (IQR, 96-411). At arterial CT phase, kurtosis at SSF = 4 (hazard ratio $[$95/% confidence interval$]$ = 3.23 $[$1.35-7.71$]$ p = 0.0084) was independent predictor of overall survival. At portal-venous phase, skewness without filtration (HR $[$CI 95%$]$ = 353.44 $[$1.31-95102.23$]$, p = 0.039), at SSF2 scale (HR $[$CI 95%$]$ = 438.73 $[$2.44-78968.25$]$, p = 0.022) and SSF3 (HR $[$CI 95%$]$ = 14.43 $[$1.38-150.51$]$, p = 0.026) were independently associated with overall survival. No textural feature was identified as predictor of recurrence-free survival. In patients with resectable HCC, portal venous phase-derived CT skewness is significantly associated with overall survival and may potentially become a useful tool to select the best candidates for resection. (orig.)