The National Institute for Clinical Excellence is examining radiofrequency ablation for the treatment of colorectal metastases in the liver and will publish guidance on its safety and efficacy to the NHS in England and Wales. The Institute's Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisors, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about radiofrequency ablation for the treatment of colorectal metastases in the liver.

This document has been prepared for public consultation. It summarises the procedure and sets out the provisional recommendations made by the Advisory Committee.

Note that this document is not the Institute's formal guidance on this procedure. The recommendations are provisional and may change after consultation.

The process that the Institute will follow after the consultation period ends is as follows.

• The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
• The Advisory Committee will then prepare the Final Interventional Procedure Document (FIPD) and submit it to the Institute.
• The FIPD may be used as the basis for the Institute's guidance on the use of the procedure in the NHS in England and Wales.

For further details, see the Interim Guide to the Interventional Procedures Programme, which is available from the Institute's website (www.nice.org.uk/ip).

Closing date for comments: 27 January 2004

Target date for publication of guidance: April 2004

Note that this document is not the Institute's guidance on this procedure. The recommendations are provisional and may change after consultation.

Evidence on the safety of radiofrequency ablation of colorectal metastases in the liver appears adequate, but there are limitations in the available evidence on the efficacy of this procedure.

Clinicians wishing to undertake radiofrequency ablation of colorectal metastases in the liver should ensure that patients offered it understand the uncertainty about the procedure's efficacy and should provide them with clear written information. Use of the Institute's Information for the Public is recommended.

Clinicians should audit and review clinical outcomes of all patients having radiofrequency ablation of colorectal metastases in the liver. The British Society of Interventional Radiology will establish a database and clinicians should submit data to this database for each patient treated.

Colorectal cancer arises in the colon or rectum. It is the second most common cancer in women and the third most common cancer in men in the UK. Around 50% of colorectal cancer patients will develop recurrence within 5 years of initial diagnosis, with the liver being the most common site for metastatic disease.

The standard method of treatment for patients with liver metastases from colorectal cancer is surgical resection, but fewer than 10% of patients are suitable for operation. For patients with non-resectable hepatic metastases, treatment options include systematic chemotherapy, radiotherapy, cryotherapy, alcohol injection and laser photocoagulation.

Radiofrequency ablation (RFA) is a thermoablative technique which destroys tissue by heating cancer cells to temperatures exceeding 60°C. In RFA, temperature changes are induced using high-frequency alternating current applied via an electrode or electrodes placed within the tissue to generate ionic agitation. RFA can be applied percutaneously, laparoscopically or intraoperatively.

Local recurrence was reported in six of the nine case series studies included in a systematic review. Recurrence rates ranged from 4% (2/46), with a median of 15 months follow-up, to 55% (64/117), with a median of 18 months follow-up, in another study. Efficacy may depend on the method of access used for RFA.

Data from two small comparative series indicated that mean survival was less for patients treated with RFA than for patients treated with surgical resection. In one of these studies, however, patients with a better prognosis underwent liver resection. Survival rates were difficult to interpret because they were measured from different time points. Median survival of patients treated with RFA was reported as 37 months after treatment in one study and 44 months from diagnosis of liver metastases in the other. For patients treated with surgical resection, median survival was reported as 41 months after resection and as a mean of 54 months after diagnosis. For more details, refer to the sources of evidence (see Appendix).

One Specialist Advisor stated that RFA can prolong survival in patients with hepatic metastases, but also noted, as did the other Specialist Advisors, that RFA is more suitable for the treatment of hepatocellular carcinoma, than for metastatic disease. All the Specialist Advisors noted that there were no randomised comparisons of RFA and surgery.

Few complications were reported in the studies. The systematic review reported complication rates after RFA ranging from 0% to 33% (3/9). Complications included bile duct stricture, bowel perforation, wound infection, peritoneal seeding and postoperative bleeding. The number of patients included in the studies was small.

In one study the rate of major complications in patients with metastatic disease was 2.3% (16/693). This included 501 patients who had metastatic disease from colorectal cancer. For more details, refer to the sources of evidence (see Appendix).

The Specialist Advisors considered that RFA for colorectal metastases was likely to be safer than resection or RFA for hepatocellular carcinoma. Pain, infection and haemorrhage were listed as potential adverse events, with one Advisor stating that severe events occurred in 0-7% of patients.

The Advisory Committee commented that the evidence was based on small numbers of patients.

The Committee also noted that although the evidence suggests short-term improvement, long-term follow-up is lacking.

NICE has produced guidance on radiofrequency ablation of hepatocellular carcinoma (IPG0002), and is currently consulting on percutaneous radiofrequency ablation of renal cancer (www.nice.org.uk/ip215consultation).

The following document, which summarises the evidence, was considered by the Interventional Procedures Advisory Committee when making its provisional recommendations.

• Interventional Procedure Overview of radiofrequency ablation for the treatment of colorectal metastases in the liver, September 2003

Available from: www.nice.org.uk/ip248overview