**3.1 General considerations**

178 Liver Tumors

The route of application also influences the safety of the RFA. Although the morbidity is insignificantly higher in more invasive surgical approaches (by laparotomy/laparoscopy), the possibility to control complications during treatment, results in virtually no mortality from intraoperative RFA for both primary and metastatic liver cancer (Table 2, Mulier et al,

Morbidity 7.2 9.5 9.9 Mortality 0.5 0 0 Table 2. Morbidity and mortality rates (in %) after RFA according to the approach.

Short- and intermediate-term survival rates after RFA for small HCC are as high as 100% and 98% for 1- and 2-years, with corresponding local recurrence-free rates of 98% and 96% respectively (Lencioni et al, 2003). However with time progression and for medium- and large-sized HCC the results worsened sharply. Except from the lower complete ablation rates obtained in larger lesions, this situation is explained by the frequent presence of microscopic satellite tumor nodules in HCC. In small HCC microscopic tumor extends more than 1 cm beyond visible tumor borders in 60% of patients. In larger lesions this microscopic extension is more than 2 cm in 67% (Lai et al, 1993). It is important to note also that even in early HCC < 2 cm microscopic portal vein invasion is present in 25% of lesions (Kojiro, 2002). According to the above data it is reasonable to recommend RFA with at least 1.5 cm security ablation margin for small HCC and with ≥2.5 cm margin for larger lesions, with concomitant inflow- and/or outflow control during ablation. In cases with bilobar/multiple tumors RFA can be recommended as an adjunct to surgical resection or as an alternative treatment option if the disease is deemed inoperable at laparotomy/laparoscopy. RFA can be a valuable treatment option for patients with unresectable HCC up to 8 cm. Surgical approach offers significantly better local control rates compared with percutaneous RFA independent of tumor size. Thus percutaneous RFA should be reserved for patients who

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

percutaneous RFA RFA by laparotomy RFA by laparoscopy

2002).

refuse or cannot tolerate surgery.

**2.2 Liver metastases** 

Irrespective whether RFA is planned or not, any operation for liver tumor begins with through exploration of abdominal cavity for presence of previously unrecognized extrahepatic disease. Exploration of the liver with intraoperative ultrasound (IOUS) is a key step of the operation. All of the current imaging studies, including PET-CT, have well known limits to detect small hepatic and extrahepatic lesions compared with intraoperative staging, which includes IOUS. The latter fact ultimately adds unpredictable bias in estimating "new" lesions in any study of percutaneous RFA of liver metastases (Elias et al, 2005). In our study, as in many others IOUS demonstrates significantly higher sensitivity compared with other diagnostic methods for detection of hepatic lesions (Table 3; Julianov, 2008). More than 90% of the missed lesions are < 1cm and frequently had subcapsular location.


Table 3. Sensitivity of different diagnostic methods for detection of hepatic tumors.

Resectable extrahepatic disease is not longer considered as a contraindication for liver surgery. However in most cases the presence of unresectable extrahepatic disease is a contraindication for a liver-directed procedure. Currently the exception from this rule can be made for some patients with peritoneal carcinomatosis, if cytoreductive surgery plus intraperitoneal chemotherapy can be performed simultaneously with the liver-directed surgical treatment. In every case any attempt should be made initially for R0 resection even as a staged procedure. Survival rates following two-step hepatectomy for liver metastases still are better than those of combined RFA+liver resection procedures. RFA is recommended in some cases before portal vein embolisation to control small centrally placed lesion in the planned future liver remnant. When R0 hepatectomy deemed impossible RFA+resection can be considered. The aim of the procedure is to resect as much as possible of the lesions, treating smaller and centrally placed ones with RFA in order to preserve sufficient amount of residual healthy liver. However in patients with unresectable recurrence after liver resection, in high-risk patients with severe comorbidities or in those refusing hepatic resection RFA is a treatment option as a sole procedure (Figure 4).

Fig. 4. Follow-up CT after intraoperative RFA of recurrent colorectal liver metastases after previous resection (A), and of colorectal metastases in a high-risk patient (B) .

In selected patients with synchronous bilobar metastases and resectable extrahepatic disease simultaneous RFA plus liver and extrahepatic resection can be safely performed (Julianov et al, 2004, 2006). A substantial survival advantage can be expected in patients in whom local control is achieved with RFA/RFA+resection, compared with those patients treated with chemotherapy only. In our study of patients with liver metastases there were no 2-year survivors between patients deemed unresectable at operation and further treated with chemotherapy only. For comparison - the 3-year survival rate for patients treated with liver resection alone was 71% vs. 34% for those treated with combined RFA+resection or RFA alone. However the mean number of liver metastases was 2.5 in the resection group vs. 5 in the combined treatment group (Julianov, 2009).
