Dynamic evaluation and quantification of microvascularization during degradable starch microspheres transarterial Chemoembolisation (DSM-TACE) of HCC lesions using contrast enhanced ultrasound (CEUS): A feasibility study

Abstract

To evaluate the time dependent changes of microcirculation in hepatocellular carcinoma (HCC) lesions during degradable starch microsphere (DSM)-TACE using contrast enhanced ultrasound (CEUS). A total of 48 CEUS examinations were performed (1-5 MHz, convex probe) in 6 selected patients who underwent DSM-TACE with EmboCept®S for the treatment of HCC lesions. I.v. application of ultrasound contrast media was performed before and 24 hours post embolization. In addition i.a. contrast application was performed via the angiographic catheter right before and after the embolization and during a follow up time of 2 hours every 30 minutes. The capillary circulation of the treated HCC lesions was analyzed and quantitative perfusion analysis was performed using a perfusion software by two experienced radiologists in consensus. A significantly reduced microvascularization was seen right after DSM-TACE in all cases using CEUS. The reduction of PEAK, RBV (regional blood volume) and RBF (regional blood flow) compared to preembolization values was highly significant. Mean PEAK was 34.3 ± 13.1 prior to embolization and 9.4 ± 9.1 post embolization (p < 0.001). Mean RBV was 446.5 ± 122.4 prior to embolization and 70.9 ± 23.8 post embolization (p < 0.001). The corresponding figures for RBF were 34.7 ± 13.4 prior- and 4.8 ± 3.4 post embolization (p < 0.001). During follow up a stepwise revascularization of the lesions was documented: 90 minutes post embolization perfusion parameters were not significantly different from prae-embolization values. In this feasibility study, capillary perfusion quantification of HCC lesions after DSM-TACE could be demonstrated using CEUS. Using quantitative perfusion analysis it was possible to quantify the transient embolizing effect of DSM-TACE.