Results from two studies have demonstrated that radiofrequency ablation (RFA) is an effective treatment option for early-stage cancer. The studies examined the outcomes of RFA vs surgery in treating hepatocellular carcinoma and RFA in treating pulmonary tumours. The outcomes were presented by Professor Riccardo Lencioni, University of Pisa, Italy, at the recent annual meetings of the Society of Interventional Radiology (SIR), in Toronto, Canada, and European Congress of Radiology, in Vienna, Austria.
According to three-year data presented in Toronto, RFA is as effective as surgical resection in terms of overall patient survival and tumour recurrence in the treatment of single small hepatocellular carcinoma in patients with liver cirrhosis. Lencioni commented, "This study is important because it shows that patients who receive RFA can have the same life expectancy as patients in similar condition who undergo surgery."
A total of 162 patients were recruited into the study, comprising 38 surgical and 124 RFA cases. The primary endpoint of the study was overall survival and included secondary endpoints of local tumour progression and tumour recurrence. Eligible patients were those with Child-Pugh class A cirrhosis and uninodular hepatocellular carcinoma smaller than 5cm.
In the study, matching criteria were date of diagnosis, age at diagnosis, tumour size, and serum alpha-fetoprotein level. Although the local tumour progression rate in the RFA group was higher than in the surgical group, the incidence of tumour recurrence and patients' overall survival were similar. Overall survival rates in the resection group were 89% at one year and 78% at two years, compared with 97% at one year and 84% at two years in the RFA group. At three years, overall survival rates were 72% in the RFA group versus 65% in the surgical resection group.
"RFA is increasingly accepted as the best treatment option for patients with early-stage hepatocellular carcinoma when surgical resection is precluded," said Lencioni.
Previously, surgical resection was considered the first-line treatment for patients with small uninodular hepatocellular carcinoma and well-compensated liver cirrhosis. However, the surgical route does have its limitations. Lencioni explained that in 90% of patients, resection is not the best option. Most patients with liver cancer cannot tolerate surgical resection owing to the limited functional reserve of their liver caused by the co-existing cirrhosis. In direct contrast, RFA offers patients a non-surgical option that preserves healthy tissue. In addition, the procedure is well tolerated and has a shorter recovery time than surgery, with most patients resuming their usual activities in a few days. It can also be repeated as needed to control tumour growth in case of relapse or to treat newly developed tumours.
"This study is important because it shows that patients who receive RFA can have the same life expectancy as patients in similar condition who undergo surgery. It is important for the medical community to be aware that this option should be offered as early as possible in the course of this disease," he added.
"The key here is that we know in advance who is more likely to develop liver cancer (those with cirrhosis or chronic hepatitis). The recommendation is that all these patients undergo periodic examination with imaging to detect the emergence of the tumour at an early stage, before symptoms occur. Otherwise, it will be too late for RFA to obliterate the cancer," Lencioni concluded.
Dr Jelle Kylstra, vice president and medical director of RITA Medical Systems, commented, "According to the case-control study, for this group of patients with solitary primary liver tumours, RFA provides survival comparable to the traditional gold standard treatment of surgical resection. We believe that patients realise this benefit without the complications and morbidity often associated with surgery."
In an earlier presentation at the European Congress of Radiology, Lencioni revealed the results from the Radiofrequency Ablation of Pulmonary Tumors Response Evaluation (RAPTURE) trial. The study was a prospective, multi-centre clinical trial, designed to assess the feasibility, safety and effectiveness of RFA to treat non-small cell lung cancer (NSCLC) and pulmonary metastases. In total, the study recruited 106 patients who were non-surgical candidates, 33 presenting with primary non-small cell lung cancer (NSCLC), 53 presenting with colorectal cancer (CRC) metastases and 20 presenting with metastases from other primary malignancies. Complete ablation of macroscopic tumour as evidenced at 3-month computed tomography (CT) was achieved in 173 of 186 tumours.
The results revealed that there were no procedure-related deaths. Overall survival was 69% at one year and 49% at two years in patients with NSCLC; and 86% at 1 year and 62% at 2 years in patients with CRC metastases. Cancer-specific survival was 91% at 1 year and 91% at 2 years in patients with NSCLC; and 88% at 1 year and 72% at 2 years in patients with CRC metastases.
Lencioni commented that the results show that RFA yields high local tumour control rates in patients with small lung malignancies and is associated with acceptable morbidity. In addition, he said that cancer-specific survival outcomes supported the use of RFA in patients who were unable to support resection. However, Lencioni emphasised that futureprospective, possibly randomised trials will be need to definitely establish the role of the technique with respect to chemo/radiation therapy protocols.
In both studies, RFA was performed under ultrasound guidance using 150-200W generators and expandable multi-tined electrodes, from RITA Medical Systems. This technology relies on direct temperature measurement made by an insulated outer cannula that houses nine curved electrodes of various lengths that are deployed from the trocar tip. Five of the electrodes are hollow and contain thermocouples in their tips to measure the tissue temperature. Probes tip temperatures, tissue impedance and wattage are displayed on the RF generator and are graphically recorded by a dedicated software program. Maximum power output of the RF generator, amount of electrode array deployment from the trocar, and duration of the effective time of the ablation (time at target temperature) depend on the desired volume of ablation.
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