The National Institute for Clinical Excellence is examining salvage cryotherapy for recurrent prostate cancer and will publish guidance on its safety and efficacy to the NHS in England, Wales and Scotland. 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 salvage cryotherapy for recurrent prostate cancer.

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

• comments on the preliminary recommendation
• the identification of factual inaccuracies
• additional relevant evidence.

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  The Advisory Committee will then prepare draft guidance, which will be the basis for the Institute's guidance on the use of the procedure in the NHS in England, Wales and Scotland.

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

Closing date for comments: 23 November 2004

Target date for publication of guidance: February 2005

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

Salvage cryotherapy may be used to treat carcinoma of the prostate that has been refractory to other treatments, for example, radiotherapy or hormone therapy.

Treatment options for locally recurrent prostate cancer after radiotherapy are limited and include salvage radical prostatectomy, salvage cryotherapy and salvage brachytherapy.

Salvage cryotherapy may be performed under general or spinal anaesthesia. A warming catheter is initially inserted into the urethra to prevent it being damaged by the cold. Cryoneedles or probes are inserted into the prostate, using imaging for guidance. Temperature monitor probes may also be placed percutaneously through the perineum. Argon gas is then circulated through these needles or probes, generating very low temperatures and causing the formation of ice around the prostate gland which destroys the affected tissue. Newer cryotherapy techniques allow for these needles to be removed or repositioned so that the frozen zone conforms to the exact size and shape of the target tissue. After the procedure, a suprapubic catheter is inserted and left in place for 1-2 weeks, depending on the post-void residual urine volume.

Prostate-specific antigen (PSA) is a protein produced by both normal and cancerous cells in the prostate gland. Reduction in the PSA level may be used to monitor response to treatment and, along with negative biopsies, is used as a surrogate marker for improved clinical outcomes in trials of salvage cryotherapy. Various efficacy outcome measures were used in the studies identified, making comparisons of efficacy across studies difficult.

In one study, nadir PSA < 0.5 ng/ml was reported in 97% (114/118) of patients who had undergone salvage cryotherapy; in another study, a level of < 0.1 ng/ml was reported in 60% (26/43) of patients. These studies included patients with recurrent prostate cancer or rising PSA levels, and those who were undergoing salvage therapy.

Complication rates varied substantially among the studies and there is some evidence to suggest that complications have decreased with improvements in technique and instrumentation. Among the studies identified, the following complications were reported: impotence in 72% (108/150) and 86% (12/14) of patients incontinence in 8% (3/38) of patients; perineal and/or rectal pain in 18% (27/150) to 39% (15/38) of patients. Other reported complications from the case series included fistula formation in 1% (2/150) to 3% (4/118 and 2/59) of patients. For more details, refer to the sources of evidence (see Appendix).

The Specialist Advisors listed the main complications as urinary incontinence, impotence, rectal injury and fistula formation. However, severe complications are rarer and comparison needs to be made to complication rates in alternative options.

It was noted that the technology for this procedure is continuing to evolve.

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

Interventional procedures overview of salvage cryotherapy for recurrent prostate cancer, June 2004

Available from: www.nice.org.uk/ip130overview