Local therapies for hepatic metastases

The liver is one of the most common sites for metastatic disease, and optimal management of hepatic metastases often requires a multidisciplinary approach. Most commonly, liver metastases are derived from a colorectal or neuroendocrine primary tumor. Liver resection with curative intent is standard for resectable cases, but unfortunately most patients are not initially resectable because of the size, location, and/or extent of disease; inadequate remnant liver volume; or comorbidities. For patients with liver-limited or liver-dominant colorectal liver metastases (CRLM), the current challenges are to use different locoregional treatments to convert some borderline unresectable cases to resectable, and improve local control and overall survival. Although neuroendocrine liver metastases (NELM) may behave in a relatively indolent manner from an oncologic perspective, significant morbidity may be caused by excess hormone production when compared with metastatic liver disease from other primaries, and liver-directed treatment may be beneficial in reducing symptoms and perhaps extending survival. In the multidisciplinary management of patients with liver metastases, local therapies are especially important. Local approaches may be complementary (ie, portal vein embolization) or an alternative (ie, ablation, hepatic arterial infusion, selective radioembolization, and stereotactic body radiotherapy) to surgical resection. This article evaluates the available evidence on current regional strategies for managing patients with liver metastases, with an emphasis on CRLM and NELM, highlighting the clinical usefulness and limitations of each modality.