Hyperbaric oxygen therapy for late radiation tissue injury
Abstract
Background
Cancer is a significant global health problem. Radiotherapy is a treatment for many cancers and about 50% of patients having radiotherapy with be long‐term survivors. Some will experience late radiation tissue injury (LRTI) developing months or years later. Hyperbaric oxygen therapy (HBOT) has been suggested as a treatment for LRTI based upon the ability to improve the blood supply to these tissues. It is postulated that HBOT may result in both healing of tissues and the prevention of problems following surgery.
Objectives
To assess the benefits and harms of hyperbaric oxygen therapy for treating or preventing late radiation tissue injury.
Search methods
We searched The Cochrane Central Register of Controlled Trials (CENTRAL Issue 3, 2008), MEDLINE, EMBASE, CINAHL and DORCTHIM (hyperbaric RCT register) from inception to August 2008.
Selection criteria
Randomised controlled trials (RCTs) comparing the effect of HBOT versus no HBOT on LRTI prevention or healing.
Data collection and analysis
Three review authors independently evaluated the quality of the relevant trials using the guidelines of the Cochrane Handbook and extracted the data from the included trials.
Main results
Eight trials contributed to this review (566 participants). For pooled analyses, investigation of heterogeneity suggested important variability between trials. From single studies there was a significantly increased chance of improvement or cure following HBOT for radiation proctitis (relative risk (RR) 1.72, 95% confidence interval (CI) 1.0 to 2.9, P = 0.04, numbers needed to treat (NNT) = 5), and following both surgical flaps (RR 8.7, 95% CI 2.7 to 27.5, P = 0.0002, NNT = 4) and hemimandibulectomy (RR 1.4, 95% CI 1.1 to 1.8, P = 0.001, NNT = 5). There was also a significantly improved probability of healing irradiated tooth sockets following dental extraction (RR 1.4, 95% CI 1.1 to 1.7, P = 0.009, NNT = 4).
There was no evidence of benefit in clinical outcomes with established radiation injury to neural tissue, and no data reported on the use of HBOT to treat other manifestations of LRTI. These trials did not report adverse effects.
Authors' conclusions
These small trials suggest that for people with LRTI affecting tissues of the head, neck, anus and rectum, HBOT is associated with improved outcome. HBOT also appears to reduce the chance of osteoradionecrosis following tooth extraction in an irradiated field. There was no such evidence of any important clinical effect on neurological tissues. The application of HBOT to selected patients and tissues may be justified. Further research is required to establish the optimum patient selection and timing of any therapy. An economic evaluation should be also be undertaken. There is no useful information from this review regarding the efficacy or effectiveness of HBOT for other tissues.
PICOs
Plain language summary
Hyperbaric oxygen (HBO) for the treatment of the late effects of radiation therapy
There is a risk of serious complications developing after radiation treatment for cancer (late radiation tissue injury (LRTI). Hyperbaric oxygen therapy (HBOT) involves breathing oxygen in a specially designed chamber. It is used as a treatment to improve oxygen supply to damaged tissue and stimulate healing.
We found some evidence that LRTI affecting the head, neck and lower end of the bowel can be improved with HBOT. There is little evidence for or against benefit in other tissues affected by LRTI. Our conclusions are based on eight randomised trials with a limited number of patients. Further research is needed.
