Contrast enhanced ultrasonography in assessing the treatment response to transarterial chemoembolization in patients with hepatocellular carcinoma.

Abstract

Abstract. The last decades have known continuous development of therapeutic strategies in hepatocellular carcinoma (HCC). Unfortunately the disease it still not diagnosed until it is already at an intermediate or even an advanced disease. In these circumstances transarterial chemoembolization (TACE) is considered an effective treatment for HCC. The most important independent prognostic factor of both disease free survival and overall survival is the presence of complete necrosis. Therefore, treatment outcomes are dictated by the proper use of radiological imaging. Current guidelines recommend contrast enhanced computer tomography (CECT) as the standard imaging technique for evaluating the therapeutic response in patients with HCC after TACE. One of the most important disadvantage of CECT is the overestimation of tumor response. As an attempt to overcome this limitation contrast enhanced ultrasound (CEUS) has gained particular attention as an imaging modality in HCC patients after TACE. Of all available imaging modalities, CEUS performs better in the early and very early assessment of TACE especially after lipiodol TACE. As any other imaging techniques CEUS has disadvantages especially in hypovascular tumors or in cases of tumor multiplicity. Not far from now the current limitations of CEUS will be overcome by the new CEUS techniques that are already tested in clinical practice such as dynamic CEUS with quantification, three-dimensional CEUS or fusion techniques.

Imaging of intrahepatic progression of hepatocellular carcinoma post transarterial chemoembolization. A long-term, prospective evaluation of contrast-enhanced ultrasonography (CEUS)

“…Additional injections would increase the duration and complexity of the study. Cost is also a concern, although very small doses (1 ml) of the echo-enhancer are sufficient for high quality CEUS imaging with many modern machines [24]. Notably, IHP of non-target tumors (and consequently, its respective misdiagnosis by CEUS) is not always clinically significant.…”

“…We acknowledge that this percentage is derived from a very small number of cases, but we believe that it is realistic and it is explained by the limited ability of CEUS for complete and simultaneous hemodynamic study of multiple lesions. Previous work [19,24] has shown that a reliable evaluation of more than 3 treated tumors cannot be achieved with one or two injections of echo-enhancer. Additional injections would increase the duration and complexity of the study.…”

Usefulness of contrast enhanced ultrasound in monitoring therapeutic response after hepatocellular carcinoma treatment

“…On the contrary, when the therapy has failed zones of wellperfused residual tumour remain in the target lesion and focal contrast enhancement is detected in these areas. The residual unablated tumour appears like an irregular, eccentric or nodular peripheral enhancement [14][15][16][17] .…”

Imaging Diagnosis of Hepatocellular Carcinoma: Recent Advances of Contrast-Enhanced Ultrasonography with SonoVue®

“…However, in postablation reactions the enhancement observed during the arterial phase persists also during the portal and venous phases, without the occurrence of wash-out. Provided that venous wash-out is present before ablation, this feature may be of value [51]. A particular enhancement named "linear enhancement" has been noted [55], and is described as a linearshaped enhancement that runs from one side of a lesion to the other, passing through the center, which occurs after RF.…”

“…Residual viable tumor foci should be suspected in the instance of enhancement in a portion of a treated lesion. Even though the response to locoregional treatment is usually assessed by means of CT or MRI, the EFSUMB guidelines suggest to use CEUS due to its high accuracy (91-100%), when CT or MRI are contraindicated or inconclusive [11,[51][52][53][54]. Additionally, the possibility to detect residual viable tumor portions shortly after an ablation procedure allows re-treatment during the same session.…”