Hyperbaric oxygen therapy is the provision of oxygen which is at a pressure level higher than atmospheric pressure. The patient is placed in a pressure chamber breathing high concentration of oxygen, which results in hyperoxygenation of the blood and has been associated with improved wound healing. Hyperbaric oxygen therapy was evaluated in patients with cancer for treatment of lymphedema.
Effectiveness Not Established
Research Evidence Summaries
Gothard, L., Stanton, A., MacLaren, J., Lawrence, D., Hall, E., Mortimer, P., . . . Yarnold, J. (2004). Non-randomized phase II trial of hyperbaric oxygen therapy in patients with chronic arm lymphedema and tissue fibrosis after radiotherapy for early breast cancer. Radiotherapy and Oncology, 70(3), 217–224.doi: 10.1016/S0167-8140(03)00235-4
To examine hyperbaric oxygen in the treatment of chronic arm lymphedema after radiotherapy
Intervention Characteristics/Basic Study Process:
Patients received treatment with hyperbaric oxygen, compressed to 2.4 atmospheres absolute (ATA) in a multiplace category 1 hyperbaric chamber at Royal Hospital. Patients received 100% oxygen at pressure via a transparent hood. Total time at 2.4 ATA was 100 minutes, including two five-minute air breaks. Each participant received a total of 30 pressure exposures, treating five days per week for six weeks. The primary endpoint was an absolute change of greater than 20% in relative volume of the ipsilateral arm versus contralateral arm. The secondary endpoints were lymphoscintigraphy, patient self-assessments, and physician assessments. An unplanned endpoint was patient comments about arm softening and mobility as part of one relative change in arm volume.
- The study sample was comprised of 20 female patients and 1 male patient.
- Patients were included if they had greater than or equal to 30% increase in arm volume, were free from cancer recurrence, physical and psychologic fitness for hyperbaric oxygen, and availability for follow-up and informed consent.
- All patients had axillary or supraclavicular radiotherapy.
The study took place at Royal Marsden Hospital based on observation from a previous study at the same institution evaluating hyperbaric oxygen in radiation-induced brachial plexopathy. In that study, two of the six patients with chronic lymphedema experienced major and persistent improvement in lymphedema.
- Magnetic resonance imaging of the supraclavicular fossa, axilla, and brachial plexus was done prior to treatment to exclude recurrence.
- Subcutaneous induration within the radiotherapy volume was clinically assessed.
- Arm volume was measured using a Perometer.
- Quantitative lymphoscintigraphy was used.
- Clinical photographs were taken.
- Patient completed self-assessments using EORTC QOL (QLQ-C30 and BR23)
- Clinical assessment and Perometer measurements were taken within one week of completing 6 weeks of treatment and at 6 and 12 months after start of therapy.
- Self-assessments occurred at the same intervals as clinical assessments plus three and nine months after start of treatment.
- Lymphoscintigraphy and clinical photos repeated at 12 months only.
Compliance with treatment was 100%. All questionnaires were returned, and only two patients missed follow-up assessments (one patient was hospitalized and the other moved); as a result, 94% of patients had Perometer measures. Only 71% participated in lymphoscintigraphy because of logistics, 7% missed follow-up scan at 12 months, and one scan was erased accidentally. Three patients responded according to defined 20% or greater reduction in arm volume, 16 were nonresponders. Mean percentage reduction in arm volume was 7.68. Quality-of-life measures were not clinically significant post-treatment. Comments by participants indicated they may not have been appropriate measures. Lymphoscinitgraphy improvement showed statistically significant changes.
Patients had good compliance with the treatment plan despite rigorous treatment. Median time since completion of the treatment is 14 years, which is encouraging given improvement in lymphoscintigraphy measures and limb tissue softening (a subjective measure).
- The sample size was small.
- The study did not have a control group or comparison group.
The study has sufficient data to justify a randomized controlled trial. Careful screening of participants is needed.
Gothard, L., Haviland, J., Bryson, P., Laden, G., Glover, M., Harrison, S., . . . Yarnold, J. (2010). Randomised phase II trial of hyperbaric oxygen therapy in patients with chronic arm lymphoedema after radiotherapy for cancer. Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology, 97(1), 101–107.doi: 10.1016/j.radonc.2010.04.026
To assess the effectiveness of hyperbaric oxygen (HBO) therapy on reducing arm lymphedema in patients with early-stage breast cancer
Intervention Characteristics/Basic Study Process:
Participants were divided into the control and the experimental group at a ratio of 1 to 2, respectively. The experimental group received HBO therapy and breathed 100% oxygen at 2.4 atmospheres absolute for 100 minutes with two five-minute air breaks. The sessions were conducted 30 times in a six-week period or five times a week. Both the control and experimental groups received patient education on standard care for lymphedema and hosiery when appropriate.
- The study sample was comprised of 58 patients.
- Mean age of the control group was 62.1 years and the experimental group was 63.2 years.
- All patients had breast cancer and most (97%) had diagnosed lymphedema.
- Two patients had Hodgkin lymphoma with radiotherapy.
- Patients had finished adjuvant radiotherapy.
- Patients had a minimum of 15% increase in limb volume.
The study took place in multiple hospitals in the United Kingdom.
Phase of Care and Clinical Applications:
Patients were undergoing active lymphedema treatment.
The study used a randomized phase II study design.
- A Perometer measured limb volume.
- An 8% reduction was maintained as a clinically significant reduction in arm volume.
- Lymphoscintigraphy was performed to measure the fractional removal rate of the radioisotopic tracer at baseline and 12 months.
- Acquisitions were performed at 20, 60, 90, 120, and 180 minutes.
- The removal rate was calculated by the computer using a regression slope.
- Extracellular water content was measured at baseline and 12 months using dielectric constant measurements.
- Two measurements were taken: one third the distance from the antecubital crease to the forearm and one half the distance from the antecubital crease to the upper arm.
- Quality of life was assessed using the United Kingdom SF-36, completed before randomization into groups, at baseline, and at 3, 6, 9, and 12 months.
There was not a statistically significant change in limb volume between the control group (p = 0.64) and the experimental group (p = 0.50) at 12 months after baseline. The investigators define a positive response as an 8% reduction in arm volume. Thirty percent of the experimental group versus 18.8% of the control group responded to meet these criteria but was also statistically insignificant (p = 0.50). Lymphatic clearance rates were similar among groups and were not significant findings. Quality of life findings were similar among both groups and were not significant.
The study suggests that HBO therapy when added to best standard treatment of lymphedema in patients with breast cancer is not effective. The study does not confirm earlier reports of a therapeutic effect of HBO.
- The sample size was small, with less than 100 participants.
- The sample size for the control and experimental group were different, which could have affected the statistical analysis comparison and leaves room for imbalances.
- The study had a risk of bias because it had no blinding and the sample characteristics.
- The findings are not generalizable.
- The average time from radiotherapy treatment post-operatively to participation in the study was 12 years, which may also effect the results of remodeling of fibrotic tissues from HBO.
The study suggests that HBO therapy is an ineffective therapy for treating lymphedema in patients with breast cancer. The therapy should not be enacted into practice. Nursing researchers should analyze the randomized trial and non-randomized trials of this treatment program to identify confounding variables that may have made the non-randomized trial results significant and the randomized trial results not significant. If the study is repeated a larger sample size should be used.