Efficacy of contrast-enhanced US versus CT or MRI for the therapeutic control of percutaneous radiofrequency ablation in the case of hepatic malignancies.

ABSTRACT

PURPOSE: The goal of this study was to assess the informative value of contrast-enhanced ultrasound after radiofrequency ablation (RFA). Patients who had undergone RFA of malignant liver tumors were followed up with contrast-enhanced sonography (CEUS), computed tomography (CT) and/or magnetic resonance tomography (MRI), and the outcomes were compared. MATERIALS AND METHODS: 76 patients undergoing 194 RFAs for 118 hepatic neoplasms (n = 55 HCC, n = 63 metastases) in the course of a 7-year period were examined post-interventionally using CEUS and CT or MRI. During follow-up (gold standard of evaluation), contrast agent rim accumulations with a diameter greater than 5 mm and a growth rate of at least 25 % were counted as a recurrence. RESULTS: CEUS-CT comparison group A total of 65 scan pairs were compared. In 54 cases (83.1 %) the findings were the same with either method. In 7 cases (10.8 %) CEUS confirmed the correct diagnosis, and in 2 cases (3.1 %) only CT was correct. In 2 cases (3.1 %) both methods yielded incorrect results. Diagnostic accuracy (DA) CEUS 93.8 %, CT 86.2 %. CEUS-MRI comparison group In 23 cases (88.5 %) of a total of 26 scan pairs, the findings were the same for both CEUS and MRI. In 3 discordant cases only CEUS confirmed the correct diagnosis (3 cases, 11.5 %). Diagnostic accuracy DA (n = 26) CEUS 100 %, MRI 88.4 %. CONCLUSION: CEUS performs equally to CT and MRI in the follow-up of patients treated for liver tumors by RFA.