The
conduct of radiotherapy in an environment of hyperbaric oxygenation improved
survival in carcinoma of the urinary bladder.
Clinical Bottom Line:
1.
The addition of hyperbaric oxygenation to a regime of radiotherapy for cancer
of the bladder resulted in a significant reduction in mortality over two
years.
2.
Mortality was high in both groups.
Appraised
by: Mike Bennett, Dept of Diving and
Hyperbaric Medicine, Prince of Wales Hospital
Sydney; Friday, 11 December,
1998
Clinical
Scenario: A patient with bladder cancer
where radiotherapy is the treatment of choice.
Three-part
Question: In urinary bladder carcinoma
being treated with radiotherapy, does exposure to the radiation dose while
having hyperbaric oxygen, compared to normal air breathing, result in any
improvement in recurrence rate, mortality or morbidity?
Search
Terms: Hyperbaric oxygenation,
radiotherapy, tumours/bladder.
The
Study:
Non-blinded randomised
controlled trial with intention-to-treat.
Patients with staged bladder
cancer presenting for radiotherapy.
Control group (N = 21; 21
analysed): 6,000 rads over six weeks, giving four or five fractions each week.
No attempt to sham treatment.
Experimental group (N = 19; 19
analysed): 4,800 rads over 29-32 days in 12 fractions while breathing 100%
oxygen at 3ATA for about 40 minutes.
The
Evidence:
|
Outcome |
Time
to Outcome |
Air
Group |
HBO
Group |
Relative
risk reduction |
Absolute
risk reduction |
NNT |
|
Survival |
6
months |
0.810 |
0.895 |
10% |
0.09 |
12 |
|
95%
CI: |
|
|
|
-16%
to 37% |
-0.13
to 0.30 |
NNT=3
to INF NNH=8 to
INF |
|
Survival |
48
months |
0.048 |
0.105 |
119% |
0.06 |
18 |
|
95%
CI: |
|
|
|
100%
to -100% |
-0.11
to 0.22 |
NNT=4
to INF NNH=9 to
INF |
Non-Event
Time to outcome
P-value
Outcomes
Survival
analysis
0-27 months
P<0.05
Comments:
1. Small study did not show
significant differences at point estimates of survival.
2. Radiotherapy regime was
different between the two groups.
3. The significance for present
treatment of bladder cancer is not clear.
Expiry
date:
January 2004
