Radiofrequency ablation of liver tumors

Abstract

Radiofrequency ablation (RFA) is an alternative therapy for hepatocellular carcinoma and liver metastases when resection cannot be performed or, in the case of hepatocellular carcinoma, when transplant cannot be performed in a timely enough manner to avoid the risk of dropping off the transplant list. RFA has the advantage of being a relatively low-risk minimally invasive procedure used in the treatment of focal liver tumors. This review article discusses the current evidence supporting RFA of liver tumors, as well as the indications, complications, and follow-up algorithms used after RFA.

Keywords: hepatocellular carcinoma; liver; metastases; radiofrequency ablation; technique.

Figure 1

A 74-year-old man with cirrhosis secondary to alcohol abuse. (A) Axial T1 fat-saturated image postgadolinium demonstrates a 1.8-cm arterially enhancing lesion (arrow). (B) One month postablation, axial T1 fat-saturated image demonstrates a zone of ablation (arrow) that is larger than the original tumor with no evidence of residual enhancing tumor.

Figure 2

A 58-year-old man with hemophilia A and cirrhosis secondary to hepatitis C. (A) Axial T1 fat-saturated image postgadolinium demonstrates a 4.2-cm lesion (arrow) with a pseudocapsule that was a biopsy-proven hepatocellular carcinoma (HCC). (B) Coronal noncontrast computed tomography postablation, demonstrating an area of low attenuation at the ablation zone (star) and a subcapsular high attenuation hematoma (arrow). Two months postablation the patient underwent a liver transplant.

Figure 3

A 76-year-old man with cirrhosis secondary to hemochromatosis. (A) Axial T1 fat-saturated image postgadolinium demonstrates a 1-cm arterially enhancing lesion (arrow) that was a biopsy-proven hepatocellular carcinoma. (B) A computed tomography scan performed during the ablation procedure shows the cluster ablation electrode traversing the lung. (C) Postprocedure image demonstrates a pneumothorax (star). The track of the electrode through the lung is also seen (arrow). The patient required chest tube insertion because the pneumothorax increased in size on follow-up imaging.

Figure 4

A 51-year-old man with cirrhosis secondary to hepatitis C. (A) Contrast-enhanced computed tomography demonstrates a 2.8-cm arterially enhancing lesion (arrow) consistent with a hepatocellular carcinoma (HCC). (B) During the procedure, hydrodissection was performed with 800 mL of 5% dextrose in water (star), which displaced the lung anteriorly allowing insertion of the electrode (arrow) without traversing the lung. (C) T1 fat-saturated magnetic resonance image postgadolinium 3 months postablation demonstrates a thin enhancing rim without nodularity (arrow), compatible with a complete ablation.

Figure 5

A 72-year-old man with colorectal carcinoma. (A) Postcontrast computed tomography (CT) demonstrates a 3-cm hypoattenuating lesion (arrow) consistent with a metastasis. (B) Postcontrast CT 1-month postablation demonstrates a low attenuation ablation zone (star) with a focus of residual tumor posteriorly (arrow). (C) Postcontrast CT 6-months postablation shows the ablation zone (star) and that the focus of residual tumor has increased in size (arrow).

Figure 6

A 66-year-old man with cirrhosis secondary to alcohol dependency. (A) T1 fat-saturated image postgadolinium demonstrates a 3-cm arterially enhancing lesion (arrow). (B) Postgadolinium image 9 months postablation shows an ablation zone (arrow) without evidence of residual disease. (C) Postgadolinium image 2 years postablation demonstrates multiple areas of washout on delayed images (arrows) adjacent to the ablation zone (star), consistent with recurrent disease.