Andy Chan MD, Presenter: Nothing to Disclose

David M. Liu, Abstract Co-Author: Nothing to Disclose

Stephen Gar-Fai Ho MD, Abstract Co-Author: Nothing to Disclose

Alison Clare Harris MBChB, Abstract Co-Author: Nothing to Disclose

To determine the efficacy of contrast-enhanced ultrasound (CEUS) in guiding radiofrequency ablation of hepatocellular carcinomas (HCC).

A retrospective analysis on patients with hepatocellular carcinomas who have been treated with radiofrequency ablation (RFA) under contrast-enhanced ultrasound (CEUS) guidance at the Vancouver General Hospital (VGH) was performed. Image analyses were performed by two radiologists (AH, DL) with extensive experience in this field. CEUS images were first compared to conventional B-mode US images performed on the same session to determine the ability of CEUS to increase the conspicuity of lesions for delivery of RFA treatment. A qualitative visualization score (1=poor, 3=fair, 5=excellent) was used to grade the ability to visualize the lesions. The CEUS images were then evaluated using the most recent prior cross-sectional imaging, either contrast enhanced CT (CECT) or MRI, as the gold standard. Finally, the efficacy of the treatment was evaluated with short-term (typically 1-month) follow up imaging (either CT or MRI) for presence of residual or recurrent disease.

We currently have preliminary data from 20 patients with a total of 24 lesions with an average size of 1.8 cm, ranging from 1.0 to 3.5 cm. All 24 lesions are hypervascular on the pre-treatment CECT. 20 lesions (83%) are visualized on B-mode US with an average visualization score of 2.4, while 21 lesions (88%) are visualized on CEUS with an average visualization score of 4.0, with 16 of these lesions being more conspicious on CEUS. The CEUS enhancement and appearance are concordant with the pre-treatment CECT for 19 lesions (79%). 16 lesions have subsequent 1-month follow-up post-treatment. Based on the EASL criteria, 12 of these lesions (75%) demonstrate a complete response (CR), while the remaining 4 lesions (25%) demonstrate a partial response (PR). Further data will be collected, analyzed, and presented during the scientific presentation.

Compared to conventional B-mode US, CEUS increases the conspicuity and provides better characterization of hypervascular HCC, and provides real-time guidance of RFA with good short-term treatment responses.

CEUS can be used to provide real-time visualization of HCC to guide RFA. It also provides an alternative method of assessment to CECT and MRI, particularly in those patients with renal impairment.

Chan, A, Liu, D, Ho, S, Harris, A, The Role of Contrast-enhanced Ultrasound in Guiding Radiofrequency Ablation of Hepatocellular Carcinomas: A Retrospective Study.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11034391.html