Color Coded Perfusion Imaging with Contrast Enhanced Ultrasound (CEUS) for Post-Interventional Success Control Following Irreversible Electroporation (IRE) of Primary and Secondary Malignant Liver Lesions

Aim: Evaluation of the post-interventional success following irreversible electroporation (IRE) using a new color coded perfusion quantification software with contrast-enhanced ultrasound (CEUS) in patients with malignant lesions of the liver. Methods: Thirty-eight patients with 68 malignant liver lesions underwent IRE. All malignant lesions were investigated with CEUS before and within 24 hours following IRE to detect residual tumor tissue. The parameters analyzed by color coded perfusion quantification software were: the peak enhancement (pE), time to peak (TTP), mean transit time (mTT), rise (Ri) and wash-in area under the curve (WiAUC). Perfusion in the center, the margins of the lesions and in the surrounding liver were evaluated using these parameters. Results: Hepatocellular carcinoma (HCC) with complete ablation showed significantly different changes between the center and the margin of the lesions for WiAUC (p<0.05) and pE (p<0.01). Also significant differences were noted between the center of the lesions and the surrounded tissue for the same parameters (p<0.01). In the completely ablated metastatic lesions, significant differences were found between the center of the lesion and the margins (p < 0.01) and between the center of the lesion and the surrounding liver (p < 0.05) for WiAUC. mTT, TTP and Ri showed no significant changes between the center of the lesions, margin of the lesions or surrounding tissue. Also, no significant differences were found for these parameters in the different regions of interest for HCC or the metastatic lesions with partial ablation success. Conclusion: CEUS with perfusion imaging is a valuable supporting tool for the post-interventional evaluation of liver lesions following IRE. Focus should be placed on the peak enhancement (pE) and the wash-in area under the curve (WiAUC).