There
was no improved survival or local control with the addition of hyperbaric
oxygenation to standard radiotherapy for patients with carcinoma of the uterine
cervix.
Clinical Bottom Line:
1.
No advantage in survival or local tumour control in hyperbaric group.
Appraised
by: Mike Bennett, Dept. of Diving and
Hyperbaric Medicine, Prince of Wales Hospital
Sydney ; Friday, 27 October 2000
Clinical
Scenario: A patient with Stage II
carcinoma of the cervix suitable for radiotherapy.
Three-part
Question: For patients with carcinoma of
the cervix requiring radiotherapy, does the administration of radiotherapy in a
hyperbaric oxygen environment, compared to administration in air, result in any
improvement in survival?
Search
Terms: hyperbaric oxygenation,
carcinoma of the cervix, radiotherapy
The
Study:
Double-blinded concealed
randomised controlled trial intention-to-treat unknown.
Stage III or Stage IIb carcinoma
of the cervix and suitable for both DXRT and HBOT. Patients excluded if
intercurrent illness likely to reduce survival after treatment, if deemed
unlikely to return for follow-up or if over 75 years.
Control group (N = 173; 168
analysed): DXRT total dose 45Gy over 10 fractions in 5 weeks OR 58Gy in 27
fractions over 5.5 weeks. Some patients also had intra-cavitary treatment as
well.
Experimental group (N = 147; 142
analysed): Same DXRT as above, but treatment administered while in a hyperbaric
oxygen environment at 3 ATA for about 20 minutes.
The
Evidence:
|
Outcome |
Time to
Outcome |
Air group |
HBO group |
Relative
risk increase |
Absolute
risk increase |
Number
needed to treat |
|
Death |
5 years |
.62 |
.67 |
8% |
0.05 |
20 |
|
95% CI: |
|
|
|
-9% to 15% |
-0.06 to 0.16 |
NNH = 6 to INF
NNT = 18 to INF |
|
Death
|
10 years |
.69 |
.77 |
12% |
0.08 |
12 |
|
95% CI: |
|
|
|
-3% to 26% |
-0.02 to 0.18 |
NNH = 6 to INF
NNT = 54 to INF |
|
Local
recurrence |
5 years |
.58 |
.59 |
2% |
0.01 |
100 |
|
95% CI: |
|
|
|
-17% to 21% |
-0.1 to 0.12 |
NNH = 8 to INF
NNT = 10 to INF |
Comments:
1. Less than half of the total
case load were entered into the trial.
2. Radiation morbidity as cause
of death was more common if randomised to oxygen or 10 fractions
3. Interpretation of findings
difficult due to differential patient entry criteria and treatment options
during the study period.
Expiry
date:
January
2004
References:
1. Dische S, Saunders M, Sealy
R, Werner I, Verma N, Foy C, Bentzen S. Carcinoma of the cervix and the use of
hyperbaric oxygen with radiotherapy: a report of a randomised controlled trial.
Radiotherapy and Oncology 1999; 53:93-98.
