Therapeutic Value of Radiofrequency Ablation of Hepatic Malignant Tumors
Patients with primary and secondary malignancies of the liver are common. Liver is involved in 40% of adult patients who have primary tumors extrahepatic, and in cases with primary tumors, drained by the portal venous system (pancreas, large bowl, and stomach), liver is involved in as much as 75% of patients. Hepatocellular carcinoma (HCC) are the most common primary liver tumor, and metastatic liver tumours most often generate from colorectal carcinoma. Without treatment the median survival of HCC is 4 to 20 months and for CRM it is 5 to 13 months.Surgical resection of hepatic tumours is the best treatment modality with potential for cure in selected patients. According to a recent report from March 2006, the overall survival after hepatic resection of colorectal metastases at 1, 5, and 10 years was 93%, 47%, and 28%, respectively. In fact, only 5% to 15% of newly diagnosed primary or secondary liver malignancies are amenable to surgical resection. Use of other methods which do not involve resection has been in focus and can be divided into systematic techniques such as chemotherapy and arterial infusion chemotherapy and direct ablation treatments such as cryotherapy, ethanol injection and thermal ablation by use of lasers, microwaves or radiofrequency. RFA involves the localized application of alternating current that creates a marked agitation of ions in the target tissue. Agitation results in frictional heat around the electrode and thermal coagulative necrosis.The aim of the present study was to investigate the treatment efficacy of RFA and associated complications, based on available literature.The included studies were heterogeneous and clear conclusions were difficult to draw. The best overall survival for RFA treatment according to the included studies was 93% for 1-year, 69% for 2-years, and 63% for 3-years. Major complications ranged from 0.9% to19.8% and minor from 4.7% to 32.5%. At present the radiofrequency ablation seems to be a promising therapy, but these results are based on the uncontrolled non-randomised trials. Randomised trials are not available to support the use of this technique. After search in Cochrane database only one review was present and this too compared different treatment modalities for the treatment of HCC. Therefore conclusive evidence based on randomised trials for potential survival benefit from RFA of hepatic tumors is awaited.