Asian Conference on Tumor Ablation Guidelines for Hepatocellular Carcinoma

Abstract

Globally, the incidence and associated mortality of primary liver cancer have been steadily increasing. Currently, 80% of cases are found in Asia. Curative resection is applicable in only 20% of patients; therefore, various nonsurgical treatment modalities have been developed. Image-guided percutaneous liver tumor ablation is regarded as the best option for treating early-stage hepatocellular carcinoma (HCC). However, skills and knowledge in ablation can vary among operators. Furthermore, Asia has the highest number of ablation procedures for HCC and the largest number of doctors performing ablation worldwide. Thus, the Asian Conference on Tumor Ablation has developed guidelines for HCC. These guidelines will discuss indications, pre-ablative diagnosis and planning, techniques, peri-ablative management, evaluation of therapeutic effectiveness, complications, post-ablative follow-up, prevention of recurrence, and treatment of recurrence for HCC.

Keywords: Ablation; Guidelines; Hepatocellular carcinoma.

Fig. 1.

Schematic representation of gross pathological types of HCC (reproduced with permission from the Liver Cancer Study Group of Japan [42]). HCC, hepatocellular carcinoma.

Fig. 2.

CEUS image of a typical HCC. The US contrast agent Sonazoid demonstrates hypervascularity during the arterial phase (middle) and washout during the late vascular phase (right), compared to the non-contrast B mode image of the tumor (left).

Fig. 3.

Fusion image guidance during ablation. Fusion imaging combines real-time US images with previously acquired cross-sectional images, such as CT or MRI. By synchronizing the two imaging modalities, it allows the operator to view both the high-resolution, static images from CT or MRI alongside the real-time, dynamic US images. Caution: while fused images of MRI/CT and US appear similar, they are not identical. Therefore, during ablation, points are marked on the real-time US image. As a result, the line may appear differently on the fused MRI/CT image, as shown in these figures.

Fig. 4.

Artificial ascites and artificial pleural effusion allow a tumor located beneath the diaphragm, which would otherwise be obscured by lung air, to become visible on US. Additionally, artificial ascites, as seen in this image, creates space between the diaphragm and the ablated area, helping to reduce pain during and after the procedure by minimizing heat conduction to the diaphragm.