Grenz rays therapy for inflammatory skin conditions (interventional procedures consultation)

NATIONAL INSTITUTE FOR HEALTH AND CLINICAL EXCELLENCE

Interventional Procedure Consultation Document

Grenz rays therapy for inflammatory skin conditions

Grenz rays therapy involves exposing the skin to low-energy, non-penetrative electromagnetic radiation. It is used in several inflammatory skin conditions (including certain localised forms of eczema and psoriasis) when other therapies have failed. These conditions can severely impair quality of life, with effects that include redness, itching and blistering.


The National Institute for Health and Clinical Excellence is examining grenz rays therapy for inflammatory skin conditions and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. The Institute'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 grenz rays therapy for inflammatory skin conditions.

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  • The Advisory Committee will then prepare draft guidance which will be the basis for the Institute's guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.

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: 24 July 2007
Target date for publication of guidance: November 2007


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


1 Provisional recommendations
 
1.1 Current evidence on the efficacy of Grenz rays therapy for inflammatory skin conditions is very limited and is difficult to assess since reported patient groups are heterogeneous and patient numbers are small. With regard to safety, there is some concern about the risk of skin malignancy in the long term. Therefore, clinicians wishing to use Grenz rays therapy should do so only in research involving controlled trials, closely observed case series and/or contribution to a register. Studies should include clear definitions of treatment indications and quality of life measures.
1.2 Grenz rays therapy should be offered only to carefully selected patients whose inflammatory skin conditions have failed to respond to other treatments.
1.3 The Institute may review this procedure in the light of further research.
 
 
2 The procedure
 
2.1 Indications
 
2.1.1 Grenz rays therapy has been used for a large number of benign inflammatory skin conditions refractory to conventional treatment, including eczema (synonymous with dermatitis) and psoriasis.
2.1.2 Treatment for inflammatory skin conditions depends on the type and severity of the inflammation and its location. Topical treatments for eczema include emollients, steroid creams and ointments, and non-steroid immunomodulators. Non-topical treatments used for severe eczema that has not responded to other interventions include ultraviolet B (UVB) light therapy, psoralen and ultraviolet A (PUVA) light therapy, oral corticosteroids and immunosuppressant medication. Superficial X-ray treatment has also been used, but this is different from Grenz rays therapy.
2.1.3 Topical treatments for psoriasis include emollients, coal tar, keratolytics (salicylic acid), steroid creams or ointments, dithranol and ointments containing vitamin D or A derivatives. Non-topical treatments include UVB light therapy, PUVA light therapy, oral tetracyclines, retinoids and immunosuppressants. More recently developed treatments for severe plaque psoriasis that has not responded to other interventions include subcutaneous injections of the cytokine inhibitors efalizumab or etanercept. The Institute has produced guidance on these agents and other treatments for eczema and psoriasis (see section 3.1).
 
 
 
2.2 Outline of the procedure
 
2.2.1 Grenz rays are a form of electromagnetic radiation with a relatively long wavelength, between ultraviolet rays and X-rays. The penetrative power of Grenz rays is very low and does not extend deep into the dermis of the skin. During treatment the patient typically lies on a treatment couch and a Grenz rays machine directs rays towards the affected area of skin from an approximate distance of 10-20 cm. A cone can be used to restrict exposure to designated areas and to ensure that the distance between the machine and the skin remains constant. Treatment is usually performed on an outpatient basis over a number of sessions, each lasting no more than a few minutes.
 
 
 
2.3 Efficacy
 
2.3.1 Three randomised controlled trials (RCTs) studied patients with eczema of the hands. One RCT which compared Grenz rays with superficial X-ray treatment, reported that 52% (13/25) of patients thought there was no difference between the treatments in improving the severity of eczema on their hands 3 weeks after treatment. Of the remaining patients, 44% (11/25) considered superficial X-ray treatment to be better and 4% (1/25) considered Grenz rays to be better (p < 0.05) 3 weeks after treatment. However, this difference was no longer significant at 18 weeks with 30% (6/20) of patients reporting superficial X-ray treatment to be better and 5% (1/20) reporting Grenz rays to be better. An RCT which compared Grenz rays on one hand with a sham procedure on the other reported no significant difference between Grenz rays and sham treatment, with 89% (16/18; observer's assessment) and 56% (10/18; patient's assessment) of patients showing equal improvement in both hands 18 weeks after treatment. Another RCT comparing Grenz rays with a sham procedure reported that 87% (20/23) of patients had a better response with Grenz rays than with sham treatment 10 weeks after the start of treatment (p < 0.001).
 
2.3.2 A further RCT compared Grenz rays treatment for one side of the head with a sham procedure for the other in patients with scalp psoriasis. Complete healing was reported in 88% (14/16) of patients on the side of the scalp which received Grenz rays. There were no patients reported with better outcomes on the sham-treated side of the scalp compared with the Grenz-rays treated side. In a second RCT comparing Grenz rays on one side of the head with a sham procedure for the other in patients with symmetrical psoriasis, 67% (12/18) of patients reported that Grenz rays therapy was superior to sham treatment and 33% (6/18) reported no difference (p < 0.05). In a third RCT comparing Grenz rays with a sham procedure in the treatment of nail psoriasis, 36% (8/22) of patients treated with Grenz rays had a complete or slight improvement, compared with 4% (1/22) of those treated with sham (p < 0.05).
2.3.3 In an RCT comparing Grenz rays with sham treatment for pustulosis palmoplantaris 87% (13/15) of patients responded better to Grenz rays therapy on clinical evaluation at 6 weeks' follow-up (p < 0.01). For more details, refer to the sources of evidence (see appendix).
2.3.4 Three Specialist Advisers stated that Grenz rays therapy used to be widely used, but that it has been superseded by other forms of treatment. The Specialist Advisers highlighted uncertainties about some aspects of the procedure, including optimal doses, number of exposures and dosing intervals.
 
 
2.4 Safety
 
2.4.1 A cancer registry linkage study reported that, among 14,140 patients treated with Grenz ray therapy and followed up for a mean period of 15 years, there were 39 incident cases of non-melanoma skin cancer, compared with 26.9 cases expected (ratio of observed and expected cases = 1.45, 95% CI 1.03 to 1.98). Some of these patients may have been exposed to other carcinogenic treatments for their skin conditions.
2.4.2 Five RCTs reported that rates of skin pigmentation following Grenz rays therapy were 0% (0/17 and 0/25), 3% (1/30), 21% (5/24) and 23% (5/22) (follow-up periods not reported). For more details, refer to the sources of evidence (see appendix).
2.4.3 The Specialist Advisers considered the main safety concern with Grenz rays therapy to be the potential for induction of skin cancer. They noted that other treatments for these conditions are also carcinogenic. Additional potential adverse events identified by the Specialist Advisers included erythema, pigmentation and chronic radiation damage to the skin.
 
2.5 Other comments
2.5.1 Many of the published studies on Grenz rays therapy did not specify clearly the criteria that were used in patient selection, or were carried out before the availability of several contemporary treatments (see sections 2.1.2 and 2.1.3).
2.5.2 The Specialist Advisers stated that Grenz rays therapy is usually reserved for patients whose inflammatory skin conditions have proved refractory to other treatments.
 
3 Further information
3.1 The Institute has issued Technology Appraisals on the use of pimecrolimus and tacrolimus (http://guidance.nice.org.uk/TA82), and topical steroids (http://guidance.nice.org.uk/TA81) for atopic dermatitis (eczema), and on etanercept and efalizumab for the treatment of adults with psoriasis (http://guidance.nice.org.uk/TA103) A clinical guideline on atopic eczema in children is in development (http://www.gserve.nice.org.uk/guidance/index.jsp?action=byID&o=11636).
   

Bruce Campbell
Chairman, Interventional Procedures Advisory Committee
June 2007

Appendix: Sources of evidence
 

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

  • 'Interventional procedure overview of Grenz rays therapy for inflammatory skin conditions', March 2007

Available from: www.nice.org.uk/ip394overview.

This page was last updated: 30 March 2010