Liver metastases: interventional therapeutic techniques and results, state of the art

The liver is the most common site of metastatic tumour deposits. Hepatic metastases are the major cause of morbidity and mortality in patients with gastrointestinal carcinomas and other malignant tumours. The rationale and results for interventional therapeutic techniques in the treatment of liver metastases are presented. For the treatment of patients with irresectable liver metastases, alternative local ablative therapeutic modalities have been developed. Technique and results of local interventional therapies are presented such as microwave-, radiofrequency (RF)- and ultrasound ablation, and laser-induced interstitial therapy (LITT), cryotherapy and local drug administration such as alcohol injection, endotumoral chemotherapy and regional chemoembolisation. In addition to cryotherapy, all ablative techniques can be performed percutaneously with low morbidity and mortality. Cryotherapy is an effective and precise technique for inducing tumour necrosis, but it is currently performed via laparotomy. Percutaneous local alcohol injection results in an inhomogeneous distribution in liver metastases with unreliable control rates. Local chemotherapeutic drug instillation and regional chemoembolisation produces relevant but non-reproducible lesions. Laser-induced interstitial thermotherapy (LITT) performed under MRI guidance results in precise and reproducible areas of induced necrosis with a local control of 94%, and with an improved survival rate. Interventional therapeutic techniques of liver metastases do result in a remarkable local tumour control rate with improved survival results.