How Effective Are Percutaneous Liver-Directed Therapies in Patients with Non-Colorectal Liver Metastases?

BACKGROUND The purpose of this review is to demonstrate the clinical indications, technical developments, and outcome of liver-directed therapies in interventional oncology of non-colorectal liver metastases. METHODS Liver-directed therapies are classified into vascular transarterial techniques such as chemoperfusion (TACP), chemoembolization (TACE), radioembolization (selective internal radiation therapy (SIRT)), and chemosaturation, as well as thermal ablation techniques like microwave ablation (MWA), radiofrequency ablation (RFA), laser-induced thermotherapy (LITT), cryotherapy, and irreversible electroporation (IRE). The authors searched the database PubMed using the following terms: 'image-guided tumor ablation', 'thermal ablation therapies', 'liver metastases of uveal melanoma', 'neuroendocrine carcinoma', 'breast cancer', and 'non-colorectal liver metastases'. RESULTS Various combinations of the above-mentioned therapy protocols are possible. In neuroendocrine carcinomas, oligonodular liver metastases are treated successfully via thermal ablation like RFA, LITT, or MWA, and diffuse involvement via TACE or SIRT. Although liver involvement in breast cancer is a systemic disease, non-responding nodular metastases can be controlled via RFA or LITT. In ocular or cutaneous melanoma, thermal ablation is rarely considered as an interventional treatment option, as opposed to TACE, SIRT, or chemosaturation. Rarely liver-directed therapies are used in pancreatic cancer, most likely due to problems such as biliary digestive communications after surgery and the risk of infections. Rare indications for thermal ablation are liver metastases of other primary cancers like non-small cell lung, gastric, and ovarian cancer. CONCLUSION Interventional oncological techniques play a role in patients with liver-dominant metastases.