Possibilities of contrast- enhanced ultrasound (CEUS) for evaluation of the success of percutaneous treatments of malignant liver lesions using special perfusion software

Aim: Using new perfusion software for evaluation of the success of percutaneous treatments of malignant liver tumor lesions with CEUS.

Material and methods: Retrospective analysis of 79 patients (66 male, 13 female; 30 – 84 years) with 140 malignant liver lesions (size 9 mm-10 cm). The lesions were metastases in 45 cases and HCC lesions in 95 cases. The success of percutaneous interventional treatments (IRE n = 40; RFA n = 33; MWA n = 36; TACE n = 31) was evaluated by CEUS with perfusion imaging using special perfusion software. CEUS was performed after bolus injection of 1 – 2.4 ml of sulfur hexafluoride microbubbles. Regions of interest (ROI) were manually placed in the centre, and the margins of the lesions as well as in the surrounding tissue. Using perfusion software Time to Peak (TTP), mean Transit Time (mTT), Rise-Time, and wash-in rate were calculated in the ROIs.

Results: There were significant differences in all cases between the centre compared to the surrounding liver tissue for the main perfusion parameters (Peak, Rise Time, wash-in) (p < 0.001). There were also significant perfusion differences for Peak and wash- in when comparing defect and margins (p < 0.001), and in Peak, Rise Time, and Wash- in when comparing liver tissue to the defect and the defect in comparison to the margins for completely treated lesions.

Conclusion: Combination of CEUS with perfusion imaging using special perfusion software enables a very critical analysis of successful treatment by percutaneous interventional procedures of malignant liver lesion.

Clinical relevance Statement: A combination of CEUS with perfusion imaging is a radiation-free possibility of controlling the success of percutaneous ablation therapies in malignant liver lesion. There are no contra-indication for ultrasound contrast-media so far.