**2.2 Liver metastases**

The liver is a common site for metastases from almost all solid malignancies. Hepatic resection is the standard treatment for liver metastases from various primary sites. However curative resection is frequently precluded by insufficient volume of the planned future liver remnant. Hepatectomy is not useful also in patients in poor general condition or in those who refuse liver resection. In these circumstances RFA was intensely explored as a treatment option for metastatic liver disease in unresectable cases. Currently RFA is used for treatment of unresectable liver metastases from different primaries including colorectal, neuroendocrine, sarcoma, breast etc. (Livraghi et al, 2003; Pawlik et al, 2006; Sutherland et al, 2006). Almost all of the published clinical data show that RFA can improve survival in patients with metastatic liver cancer compared with chemotherapy alone. In our study in 130 patients, RFA as an adjunct to surgical resection significantly improves both the local control and survival rate in primary and metastatic liver cancer (Julianov, 2009). However there is no a randomized controlled trial comparing RFA with liver resection for metastatic liver disease. For many reasons such a trial does not seem ethical to be conducted in a near future (Julianov & Karashmalakov, 2011). It is clear that RFA still cannot replace hepatic resection in the treatment of the liver metastases. For example - incomplete necrosis rates after percutaneous RFA for colorectal liver metastases reach 40% even in the treatment of small lesions <3 cm by most experienced hands (Livraghi et al., 2003). Moreover, the MD Anderson Cancer Center group reports stressing and still poorly explained data: no 5-year disease-free survivors in the RFA-treated group of 30 patients with solitary colorectal liver metastasis, even among patients with lesions < 3 cm. The comparison with the results of the liver resection in the same report clearly demonstrates that resection determines the outcome—5-year overall- and disease-free survival 27% and 0% for RFA versus 71% and 50% for resection, respectively (Aloia et al, 2006). Regarding the route of application of RFA (percutaneous or surgical) there is evidence that short-term benefits of lower invasiveness of percutaneous RFA for liver tumors do not outweigh the longer-term higher risk of local recurrence. As mentioned above – surgical RFA results in superior local control, independent of tumor size, and percutaneous RFA should be reserved for patients who cannot tolerate laparoscopy or laparotomy (Mulier et al, 2005).
