The use of radiofrequency in cancer

Abstract

Radiofrequency ablation (RFA) provides an effective technique for minimally invasive tissue destruction. An alternating current delivered via a needle electrode causes localised ionic agitation and frictional heating of the tissue around the needle. Image-guided, percutaneous ablation techniques have been developed in most parts of the body, but the most widely accepted applications are for the treatment of hepatocellular carcinoma (HCC) in early cirrhosis, limited but inoperable colorectal liver metastases, inoperable renal cell carcinoma and inoperable primary or secondary lung tumours. The procedures are well tolerated and the complication rates low. Patients with coexistent morbidity who are not suitable for surgery are often able to undergo RFA. Most treatments in the lung, kidney and for HCC are performed under conscious sedation with an overnight hospital stay or as a day-case. Larger more complicated ablations, for example, in hepatic metastases may require general anaesthesia. Limitations of RFA include the volume of tissue that can be ablated in a timely fashion, that is, most centres will treat 3-5 tumours up to 4-5 cms in diameter. Early series reporting technical success and complications are available for lung and renal ablation. Liver ablation is better established and 5-year survival figures are available from several centres. In patients with limited but inoperable colorectal metastases, the 5-year survival ranges from 26 to 30% and for HCC it is just under 50%. In summary, RFA provides the opportunity for localised tissue destruction of limited volumes of tumour; it can be offered to nonsurgical candidates and used in conjunction with systemic therapy.

Figure 1

A theoretical projection of survival following RFA (in patients with CLOCC acceptance criteria from our database) vs published Oxaliplatin and 5FU chemotherapy results.