Radiofrequency ablation of hepatocellular carcinoma: Current status

Abstract

Ablation therapy is one of the best curative treatment options for malignant liver tumors, and can be an alternative to resection. Radiofrequency ablation (RFA) of primary and secondary liver cancers can be performed safely using percutaneous, laparoscopic, or open surgical techniques, and RFA has markedly changed the treatment strategy for small hepatocellular carcinoma (HCC). Percutaneous RFA can achieve the same overall and disease-free survival as surgical resection for patients with small HCC. The use of a laparoscopic or open approach allows repeated placements of RFA electrodes at multiple sites to ablate larger tumors. RFA combined with transcatheter arterial chemoembolization will make the treatment of larger tumors a clinically viable treatment alternative. However, an accurate evaluation of treatment response is very important to secure successful RFA therapy. Since a sufficient safety margin (at least 0.5 cm) can prevent local tumor recurrences, an accurate evaluation of treatment response is very important to secure successful RFA therapy. To minimize complications of RFA, clinicians should be familiar with the imaging features of each type of complication. Appropriate management of complications is essential for successful RFA treatment.

Keywords: Hepatocellular carcinoma; Radiofrequency ablation; Transcatheter arterial chemoembolization.

Figure 1

A 61-year-old man with 1.5-cm recurrent hepatocellular carcinoma after ablation therapy in segment 5 of the liver. A: Early-phase dynamic computed tomography (CT) scan shows recurrent tumor (circle). Non-enhanced area (arrowheads) was previously treated by radiofrequency ablation (RFA); B: Contrast harmonic ultrasound (US) using Levovist shows enhancement of viable focus of a hepatocellular carcinoma (HCC) nodule (circle); C: Portal-phase dynamic CT scan, which was obtained 3 d after RFA shows that the tumor was not enhanced, indicating complete necrosis of the lesion (arrow); D: Contrast harmonic US, which was obtained 3 d after ablation shows non-enhanced area (circle).

Figure 2

A 71-year-old man with 2.0 cm local tumor progression of hepatocellular carcinoma after radiofrequency ablation therapy in segment 8 of the liver. A: Early-phase dynamic computed tomography (CT) scan shows outgrowth pattern of locally progressive hepatocellular carcinoma (HCC) (arrow). The lesion borders an unenhanced area, which was previously treated; B: Left: Contrast harmonic Doppler ultrasound (US) using Levovist shows enhancement of local tumor progression of HCC (arrow). Therefore, an enhanced lesion can be identified as a target for the insertion of a single RF electrode; Right: B-mode US shows a HCC nodule demonstrated as a low echoic lesion with an unclear border (arrowhead).