Contrast enhanced ultrasound in assessing therapeutic response in ablative treatments of hepatocellular carcinoma.

Percutaneous ablative methods guided by imaging techniques are considered nowadays curative treatment for early HCC in patients who are not candidates for liver transplantation and surgical resection. The final goal of all ablative treatments is to achieve complete destruction of neoplastic tissue by disruption of tumor vascularity. The best way to demonstrate the efficacy of any ablative methods noninvasively is to demonstrate that the blood supply has been disrupted both inside and at the periphery of the tumor by means of imaging methods. Contrast-enhanced ultrasound (CEUS) with second generation contrast agents is almost as sensitive as CT (considered to be the gold standard) in depicting the residual tumor after an ablation. Moreover, CEUS can be used before ablation to plan the treatment, during the procedure to guide the needle insertion, or immediately after to determine whether the tumor has been ablated or needs additional treatment which can be performed in the same session.