The National Institute for Clinical Excellence is examining percutaneous radiofrequency ablation of renal cancer 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 percutaneous radiofrequency ablation of renal cancer.

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.

Limited evidence suggests that percutaneous radiofrequency ablation (RFA) of renal cancer brings about reduction of tumour bulk as assessed by computed tomography, and that the procedure is adequately safe. However, the procedure has not been shown to improve symptoms or survival.

Patient selection is important and the procedure should normally be limited to patients who are unsuitable for surgery. The procedure should only be offered after assessment by a specialist multidisciplinary team.

Clinicians wishing to undertake percutaneous radiofrequency ablation of renal cancer 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 percutaneous radiofrequency ablation of renal cancer. The British Society of Interventional Radiology will establish a database and clinicians should submit data to this database for each patient treated.

There are few symptoms in the early stages of renal cancer. Typically symptoms develop as the disease progresses. The first symptom is often blood in the urine; pain and flank mass are the other classic symptoms.

The standard treatment for renal cancer is total or partial nephrectomy. However, with the improvement of medical imaging techniques, which have increased the detection of small incidental renal tumours, less invasive procedures have emerged. These include laparoscopic partial nephrectomy, cryoablation, high-intensity ultrasound and radiofrequency ablation.

Percutaneous radiofrequency ablation may be particularly indicated in patients with small renal tumours (for example less than 4cm diameter), in whom surgery may not be well tolerated, or in patients who refuse surgery.

CT scanning or ultrasound is used for image guidance, and the tumour is destroyed by heating 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.

The evidence base for this procedure was small and based on case series studies. In a UK study of eight patients with 11 tumours, seven patients (88%) remained tumour-free at a mean follow-up of 17 months as assessed by CT. Other studies reported successful ablation as assessed by CT in 79% (19/24) to 100% (5/5) of patients at follow-up. Patient characteristics such as tumour location and size varied among the studies, as did follow-up. It was also unclear at what time point recurrence had been measured in some studies, and the lack of histological data made it difficult to interpret the long-term outcomes. For more details, refer to the sources of evidence (see Appendix.)

There was also some evidence to suggest that larger renal tumours (in general greater than 3 cm diameter) required more than one treatment session to achieve the same outcome as smaller tumours. For more details, refer to the sources of evidence (see Appendix.)

One Specialist Advisor commented that although the treatment can be repeated, the likelihood of failure increases as the size of the tumour increases. All of the Specialist Advisors considered that long-term efficacy was yet to be established because only a small number of patients have been treated by this procedure.

Haematomas were the most commonly reported complication in the studies and occurrence ranged from 5% (1/21) to 28% (8/29). Other reported complications included ureteric stricture and abdominal pain. For more details, refer to the sources of evidence (see Appendix.)

The Specialist Advisors listed the main adverse events as bleeding, infection and ureteric strictures. Seeding of the needle track with tumour cells, and injury to the adjacent bowel were also listed as potential risks.

The Advisory Committee were concerned that lack of histology and limitations of CT assessment may make it difficult to determine whether total ablation of tumours has been achieved. In addition, little is known about the natural history of small renal tumours and the survival of patients with small tumours.

The site and size of the tumour also seems important and results are likely to be better when treating smaller peripheral tumours

Further information is needed about long-term efficacy.

The use of higher-powered radiofrequency is currently being investigated.

NICE has produced guidance on radiofrequency ablation of hepatocellular carcinoma (www.nice.org.uk/pdf/ip/ipg002guidance.pdf) and is currently consulting on radiofrequency ablation of colorectal metastases in the liver (www.nice.org.uk/ip248consultation).

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

• Interventional Procedure Overview of percutaneous radiofrequency ablation of renal cancer, June 2003

Available from: www.nice.org.uk/ip215overview