Interventional procedure consultation document

Percutaneous cryotherapy for renal cancer

Treating kidney tumours by freezing (cryotherapy) through a cut in the skin

Renal cancer occurs in the lining of the very small tubes in the kidney. Cryotherapy involves applying freezing temperatures to the tumour by inserting a surgical instrument (cryoprobe), with the aim of destroying cancer cells.

The National Institute for Health and Clinical Excellence (NICE) is examining percutaneous cryotherapy for renal cancer and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. NICE’s Interventional Procedures Advisory Committee has considered the available evidence and the views of Specialist Advisers, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about percutaneous cryotherapy for renal 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 provisional recommendations
• the identification of factual inaccuracies
• additional relevant evidence, with bibliographic references where possible.

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

The process that NICE 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• The Advisory Committee will then prepare draft guidance which will be the basis for NICE’s guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.

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

Through its guidance NICE is committed to promoting race and disability equality, equality between men and women, and to eliminating all forms of discrimination. One of the ways we do this is by trying to involve as wide a range of people and interest groups as possible in the development of our interventional procedures guidance. In particular, we aim to encourage people and organisations from groups who might not normally comment on our guidance to do so.

In order to help us promote equality through our guidance, we should be grateful if you would consider the following question:

Are there any issues that require special attention in light of NICE’s duties to have due regard to the need to eliminate unlawful discrimination and promote equality and foster good relations between people with a characteristic protected by the equalities legislation and others?

Please note that NICE reserves the right to summarise and edit comments received during consultations or not to publish them at all where in the reasonable opinion of NICE, the comments are voluminous, publication would be unlawful or publication would otherwise be inappropriate.

Closing date for comments: 21 April 2011

Target date for publication of guidance: July 2011

1   Provisional recommendations

1.1  Current evidence on the efficacy and safety of percutaneous cryotherapy for renal cancer is adequate to support the use of this procedure provided that normal arrangements are in place for clinical governance, consent and audit.

1.2  This procedure should only be offered after assessment by a specialist urological cancer multidisciplinary team.

1.3  NICE encourages collection and publication of data on the outcomes of this procedure in the long term. Further research should compare the long-term outcomes of cryotherapy with those of other treatments for renal cancer.

2   The procedure

2.1  Indications and current treatments

2.1.1  The most common type of renal cancer in adults is renal cell carcinoma. Symptoms and signs may include pain and haematuria. Some tumours are identified asymptomatically, through imaging. Establishing diagnosis and assessing the prognosis of some renal tumours may be difficult.

2.1.2  Treatment options include laparoscopic (or open) partial or total nephrectomy, and ablation techniques including radiofrequency ablation (RFA).

2.2   Outline of the procedure

2.2.1  Percutaneous cryotherapy for renal cancer is carried out usually with the patient under local anaesthesia and sedation.  With suitable imaging guidance, a probe is inserted percutaneously into the tumour to deliver a coolant at subfreezing temperatures, creating an ice ball around the probe’s tip, which destroys the surrounding tissues. Each freeze cycle is followed by a heat (thaw) cycle, allowing removal of the probe. Two freeze–thaw cycles are usually performed to ablate the tumour (additional cycles may also be performed if necessary), aiming to extend the ice ball approximately 1 cm beyond tumour margins. More than 1 probe can be used.

2.2.2  The maximum renal tumour size for which cryotherapy is recommended is approximately 4 cm (small, stage I tumours).

Sections 2.3 and 2.4 describe efficacy and safety outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview, available at www.nice.org.uk/guidance/IP/934/overview

2.3   Efficacy

2.3.1  A non-randomised comparative study of 93 patients treated by laparoscopic or percutaneous cryotherapy reported no disease-related deaths over 22-month and 12-month follow-up respectively.

2.3.2  A meta-analysis of prospective and retrospective non-randomised comparative studies and case series including a total of 1375 tumours reported that significantly fewer patients treated by cryotherapy had local tumour progression (defined as radiographic or pathological evidence of residual disease after initial treatment, regardless of time to recurrence) compared with those treated by RFA during a mean follow-up of 18.7 months (5% [31/600] vs 13% [100/775], p < 0.0001). Repeat ablations were required in fewer patients treated by cryotherapy than RFA (1% [8/600] vs 9% [66/775], p < 0.0001). Fewer patients treated by cryotherapy had progression to metastatic disease but this was not significant (1% [6/600] vs 3% [19/775], p = 0.06).

2.3.3  A non-randomised comparative study of 93 patients reported that 10% (2/20) of patients who had percutaneous cryoablation and 4% (2/56) of patients treated by laparoscopic cryotherapy had persistently enhancing lesions at early follow-up suggesting incomplete ablation (all patients had further treatment; 3 patients were treated by percutaneous cryotherapy and 1 by radical nephrectomy).

2.3.4  A non-randomised comparative study of 90 patients reported ‘primary effectiveness’ (complete ablation of tumour after the initial procedure) in 90% (27/30) of patients treated by percutaneous cryotherapy and 93% (56/60) of patients treated by laparoscopic cryotherapy (p = 0.68).

2.3.5  In a non-randomised comparative study of 66 patients, there were significantly more treatment failures among the tumours treated with percutaneous cryotherapy than the tumours treated with laparoscopic cryotherapy (25% [5/20] vs 4% [2/52], p = 0.015).

2.3.6  In the non-randomised comparative study of 93 patients treated by either laparoscopic cryotherapy (n = 20), or percutaneous cryotherapy (n = 59) or RFA (n = 15), patients returned to work within 6.2, 17.5 and 4.0 days respectively. The difference between the percutaneous RFA and laparoscopic cryotherapy groups was significant (p < 0.05). 

2.3.7  The Specialist Advisers listed key efficacy outcomes as success rate of cryoablation based on radiological criteria, retreatment rates, recurrence, disease-specific and overall survival.

2.4   Safety

2.4.1  The non-randomised comparative study of 90 patients reported major complications only in those treated by laparoscopic cryotherapy (severe respiratory distress in 1, intraoperative bowel injury in 1, and postoperative atrial fibrillation in 1).

2.4.2  The non-randomised comparative study of 37 patients reported that haemorrhage requiring transfusion occurred in 11% (2/18) patients treated by percutaneous cryotherapy and 28% (5/20) of patients treated by laparoscopic cryotherapy.

2.4.3  The non-randomised comparative study of 93 patients reported significant postoperative prolonged neurapraxia in 2 patients treated by percutaneous cryotherapy (not otherwise described).

2.4.4  The non-randomised comparative study of 90 patients reported that 4 patients treated by percutaneous cryotherapy had minor procedural complications, including symptomatic perinephric haematoma, asymptomatic and self-limited urine leak identified at imaging, self-limited flank paraesthesia and neuralgia, and intercostal neurapraxia.

2.4.5  The Specialist Advisers stated that the most common complication is bleeding. They stated that pancreatic, bowel and ureteric injury are rare complications. They considered theoretical adverse events to include pneumothorax and thermal injury to the skin.

2.5   Other comments

2.5.1  The Committee noted that most studies of percutaneous cryotherapy for renal cancer included both malignant and benign lesions; and that histology was unknown for many of the lesions treated by the procedure. This made interpretation of the evidence difficult.

2.5.2  The Committee was advised that the diagnosis of malignancy is typically made by imaging, and that histology is generally not available to confirm the diagnosis; this contrasts with treatment by any kind of nephrectomy which provides tissue for histological diagnosis. 

3   Further information

3.1  This guidance is a review of IPG 207 ‘Cryotherapy for renal cancers’ published in 2007.

3.2  For related NICE guidance see www.nice.org.uk

Bruce Campbell

Chairman, Interventional Procedures Advisory Committee

March 2011

_{Personal data will not be posted on the NICE website. In accordance with the Data Protection Act names will be anonymised, other than in circumstances where explicit permission has been given.}

 _{It is the responsibility of consultees to accurately cite academic work in order that they can be validated.}