Early Detection of Local Tumor Progression after Irreversible Electroporation (IRE) of a Hepatocellular Carcinoma Using Gd-EOB-DTPA-Based MR Imaging at 3T.

This single-center retrospective study was conducted to improve the early detection of local tumor progression (LTP) after irreversible electroporation (IRE) of a hepatocellular carcinoma (HCC) using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-based 3T MR imaging and to identify helpful signal characteristics by comparing 23 patients with and 60 patients without LTP. To identify the differences in the sensitivity of MRI sequences, the specificity, positive prediction value, negative prediction value (NPV) and diagnostic odds ratio were calculated. A chi-squared test, two-tailed student's t-test and binary logistic regression model were used to detect distinct patient characteristics and variables for the prediction of LTP. LTP was mostly detected in the peripheral ablation zone (82.6%) within the first six months (87.0%). The central LTP ablation area presented more hypointensities in T1 p.v. (sensitivity: 95.0%; NPV: 90.0%) and in T1 d.p. (sensitivity: 100.0%; NPV: 100.0) while its peripheral part showed more hyperintensities in T2 BLADE (sensitivity: 95.5%; NPV: 80.0%) and in diffusion sequences (sensitivity: 90.0%). Liver cirrhosis seems to be an unfavorable prognosticator for LTP ( = 0.039). In conclusion, LTP mostly occurs in the peripheral ablation zone within six months after IRE. Despite often exhibiting atypical Gd-EOB-DTPA MR signal characteristics, T2 BLADE and diffusion sequences were helpful for their detection in the peripheral zone while T1 p.v. and T1 d.p. had the highest sensitivity in the central zone.