17. Spectrum of contrast enhanced ultrasound findings in hepatocellular carcinoma treated with locoregional therapy

Abstract

Background and Aims: Contrast enhanced ultrasound (CEUS) is an ultrasound imaging technique established for hepatic imaging. It has the ability to delineate the viable and non viable tissue in a malignant focal lesion [hepatocellular carcinoma (HCC)] subjected to locoregional therapy of transarterial chemoembolization, radiofrequency ablation or acetic acid ablation. We illustrate the spectrum of CEUS findings in HCC subjected to locoregional therapies. Methods: Patients who underwent locoregional therapy for focal HCC were subjected to CEUS after one month of therapy. CEUS was performed on Supersonic aixplorer ultrasound machine using ultrasound contrast (Sonovue, Bracco, Milan, Italy). About 2.4 ml of contrast was injected per nodule and the enhancement characteristics of the nodule was evaluated in 3 vascular phases- arterial (AP, at 15–25 s), venous (VP) at 45–90 s and delayed (DP, at 180 s). Cine recording was done. No enhancement or presence of any focus of enhancement in the treated tumor site was considered as complete response or residual disease (partial response) respectively as per the mRECIST criteria. The CEUS findings were co-related with multiphase computerized Tomography (MPCT)/Magnetic Resonance Imaging (MRI) liver. Results: CEUS could delineate the presence or absence of residual disease in treated patients of focal HCC. In patients with complete response, no enhancement was present at the tumor site and the entire treated tumor was seen as a well defined, uniformly hypodense lesion with smooth margins. In contrast, the residual disease (partial response) after treatment was seen as an enhancing (hyperdense) tissue located in different regions of the treated tumor. The findings were similar to that seen on MPCT or MRI liver. Conclusions: CEUS has the ability to assess therapeutic response in focal HCC subjected to locoregional therapy and the findings are akin to those seen on MPCT/MRI. The authors have none to declare.