Consensus Guideline of Ablation for Metastatic Liver Tumors by Taiwan Academy of Tumor Ablation

Metastatic liver tumors (MLTs) are the most common type of malignant liver tumors, primarily because the liver is a frequent target organ for metastasis. Metastatic cancer is generally considered a systemic disease, so the mainstay of treatment should be systemic therapies, including chemotherapy, targeted therapies, and immunotherapy. Currently, it is believed that a multimodal approach, combining local and systemic treatments, can improve tumor control and potentially prolong patient survival. Local treatments, in addition to surgery, include ablation therapy as one of the options. Ablation therapy has its limitations and advantages for local tumor control but can also be combined with other locoregional treatments such as surgical resection, transarterial embolization, and stereotactic body radiotherapy to manage appropriate subsets of patients. Ablation of hepatocellular carcinoma has been performed for many years. In recent years, the number of MLTs cases treated with ablation has been increasing. However, the characteristics of primary liver tumors and MLTs, as well as their responses to ablation therapy, are distinct. At present, there is no established international guideline specifically for the ablation treatment of MLTs. The consensus guidelines developed by the Taiwan Academy of Tumor Ablation (TATA) represent evidence-based medical statements. These guidelines are created and reviewed by an expert team including hepatologists, medical oncologists, radiation oncologists, and intervention radiologists through comprehensive medical literature searches, discussions, and voting. The process adheres to evidence-based standards, such as evaluating levels of evidence and grading recommendations. Furthermore, the guidelines are finalized through thorough discussions among all experts and by calculating voting consistency. In cases where clinical evidence is unclear or lacking, expert opinions are also incorporated. Additionally, the guidelines provide recommendations on the future development of ablation therapy for MLTs.