There
was no benefit in terms of survival or radiation morbidity when hyperbaric
oxygen was added to a radiotherapy regime for treatment of advanced carcinoma of
the cervix.
Clinical Bottom Line:
1.
No improvement in 5 year survival with the addition of hyperbaric oxyygen.
2.
There was no reduction in the incidence of metastases or local recurrence.
3.
There was a trend to increased radiotherapy-related morbidity associated with
hyperbaric oxygen.
Appraised
by: Mike Bennett, Dept of Diving and
Hyperbaric Medicine, Prince of Wales Hospital
Sydney; Wednesday, 17 February,
1999
Clinical
Scenario: A patient with stage III
carcinoma of the cervix presented for radiotherapy. Three-part
Question: In treating advanced cervical carcinoma with radiotherapy, does
the addition of hyperbaric oxygenation during irradiation result in any
improvement in survival?
Search
Terms: Hyperbaric oxygenation,
carcinoma of the cervix
The
Study:
Non-blinded randomised
controlled trial without intention-to-treat.
Patients with advanced carcinoma
of the cervix (Stages IIb and III), in whom radiotherapy was considered the
treatment of choice.
Control group (N = 48; 47
analysed): Three 'Cathetron' implants for radiotherapy at two weekly intervals
with 10 external fractions bracketed around the second insertion to a total dose
of 6,000rads.
Experimental group (N = 39; 36
analysed): As above, but external beam irradiation given while receiving
hyperbaric oxygenation (dose not stated).
The
Evidence:
|
Outcome |
Time
to Outcome |
Air
group |
HBO
group |
Relative
risk increase |
Absolute
risk increase |
NNH |
|
Radiation
morbidity |
2
years |
0.13 |
0.22 |
69% |
0.09 |
11 |
|
95%
CI: |
|
|
|
55%
to 100% |
-0.07
to 0.25 |
NNT=14
to INF NNH=4 to
INF |
|
death |
5
years |
.54 |
.62 |
15% |
0.08 |
12 |
|
95%
CI: |
|
|
|
24%
to 53% |
-0.13
to 0.29 |
NNT=3
to INF NNH=8 to
INF |
Comments:
1. 5 patients were analysed in
the air group when randomised to receive hyperbaric oxygen.
2. Patients not completing
therapy were excluded from analysis.
3. Survival figures were not
given in the text, but read off the figure.
4. This study follows on from
Watson et al with a change in radiotherapy regime.
Expiry date: January 2004
References:
1.
Ward AJ, Dixon B. Carcinoma of the cervix: results of a hyperbaric oxygen
trial associated with the use of the Cathetron. Clinical Radiology 1979;
30:383-387.
2.
Ward
AJ, Dixon B, Stubbs B. A clinical appraisal of hyperbaric oxygen in cervix
cancer. Proceedings of The British Institute of Radiotherapy 1978;51:150-151.
