Technology for Radiofrequency Thermal Ablation of Liver Tumors

In this review the usefulness of percutaneous radiofrequency interstitial thermal ablation of liver cancer has been evaluated. The technique has been recently improved by using modified needle electrodes (eg, expandable needle, cooled needle) that allow the ablation of tumors of less than 3.5 cm in diameter in only one session. Tumor necrosis has been shown by imaging techniques such as dynamic or spiral CT, MRI, selective hepatic angiography, ultrasonography-guided fine needle biopsy, and pathologic studies. Both in hepatocellular carcinoma and liver metastases, a complete necrosis has been obtained in more than 80% of the cases. The complication rate has been low without any mortality. In a series of hepatocellular carcinoma followed for a mean time of 23 months, median survival time has been 44 months, whereas recurrence rate was similar to that observed after surgery or ethanol injection. In two small series of metastases, the percentage of disease-free survivors at 1 year ranged from 11 to 66%. In conclusion, radiofrequency interstitial thermal ablation is a safe and effective technique for ablation of liver tumor; however, its precise role in the treatment of liver metastases needs to be defined.