"In radio frequency ablation, the heat is generated by a multi-pronged probe placed into the tumor tissue in a procedure monitored by ultrasound or computer tomography. You could say the tumor is 'boiled away' on the spot," explained Professor Riccardo Lencioni from the Radiology Department at the University of Pisa, Italy, at the kick-off press conference for the European Congress of Radiology (ECR) 2007, held at Austria Center Vienna from March 9 to 13 and attended by some 16,000 participants from 92 countries. "The advantage of RFA is the small diameter of the probes of about 1.2 millimeters and the attainable lesion size of several centimeters without shifting the probes. At the same time, bleeding is effectively stopped along the insertion path through the obliteration of potential sources of blood. This method prevents puncture channel metastases caused by the dispersion of cancer cells."

Heat treatment of metastases or tumors may be painful depending on their location and the organ involved. Patients are therefore sedated or given anesthesia for this procedure. "This method of local obliteration is well-suited for the early treatment of liver, kidney, lung, breast and bone tumors," noted Professor Lencioni. "Unlike radiation or chemotherapy, this procedure has the advantage that it can be repeated - if need be - because of the lack of systemic side-effects. Thermoablation monitored by appropriate imaging can be carried out during brief hospital stays of two to three days."

Option for Inoperable Lung Cancer

This method is becoming increasingly important, for example, in the treatment of lung carcinomas, especially in cases where surgery is out of the question. Many patients with lung carcinomas are poor surgical candidates because they are long-term smokers and have contracted co-existent secondary illnesses that would make surgery more riskly. For non-small-cell lung carcinomas, there is also a relatively high risk of recurrence even after tumors are removed surgically. In many cases, chemotherapy and radiation therapy do not yield satisfactory results either.

Successful in Liver Tumors - Alternative to Surgery

RF ablation has been used successfully in the treatment of early-stage liver tumors for six years. Professor Lencioni: "For tumors with a diameter of about three centimeters, sustainable tumor destruction has even been achieved with a single needle insertion. In terms of patients' response rates and survival rates, this procedure is comparable to conventional surgical procedures and offers an alternative to surgery."

For larger tumors in the liver, the success rate of RF ablation is just 50 percent, however. In about half the cases, the tumor spreads to adjoining tissue even after radio frequency treatment. The chances of a cure for large tumors of the liver increase with minimally invasive procedures undertaken directly in the blood vessels. This fact has led to a new treatment approach.

TACE: Transarterial Chemoembolization

Transarterial chemoembolization with drug-eluting microspheres ("Precision TACE") is an innovative treatment option for liver tumors. Professor Lencioni: "TACE is a well established treatment for liver cancer. It is based on the fact that up to 95 percent of the hepatocellular carcinomas are supplied by the hepatic arteries. Normal liver tissue, for its part, receives about two thirds of its blood supply through the portal vein and about one third from arterial blood. Chemoembolization causes the hepatic arteries to close up and the tumor tissue dies. Normal liver tissue is not affected."

In Precision TACE, doxorubicin-eluting particles are delivered to the tumor via the hepatic artery. Professor Lencioni: "Owing to the microspheres, the drug for inhibiting cell growth in the tumor is present in the liver tissue in a concentration a hundred times greater than in systemic intravenous chemotherapy. Side-effects such as vomiting or stomach pain are completely absent. Blockage of the arterial flow of blood also prolongs the period of action for chemotherapeutic agents."

Pilot Study with Doxorubicin

Studies on animal models have shown that the cytostatic agent doxorubicin can significantly increase the effect on liver tumors when combined with RF ablation. Tumor cells not completely destroyed by RF ablation are at least so weakened by the exposure to high heat that doxorubicin can take full effect and destroy the tumor completely. A pilot study is being done to determine whether or not these promising results are applicable to human beings.

"Twenty patients with a liver tumor larger than three centimeters in size were subjected to RF ablation followed 24 hours later by chemoembolization with doxorubicin. In 70 percent of the cases, the tumor was completely destroyed," reported Professor Lencioni. "Overall, the data from the pilot study appear to favor the combined application of RF ablation and transarterial chemoembolization to combat hepatocellular liver carcinoma. The combined method also has an excellent safety profile. The procedure has low complication rates while offering a good quality of life and shortening the hospital stay."

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