Hyperbaric
oxygenation and a smaller number of fractions for irradiation was not associated
with improved survival or local recurrence rate in carcinoma of the cervix.
Clinical Bottom Line:
1.
No evidence of a benefit with smaller number of fractions and hyperbaric
oxygen with regard to survival or local recurrence rates.
2.
A trend to improved local control rate in those actually receiving hyperbaric
oxygen was not statistically significant.
3.
There was also a trend in the oxygen group to a greater risk of treatment
complications.
Appraised
by: Mike Bennett, Dept of Diving and
Hyperbaric Medicine, Prince of Wales Hospital, Sydney; Friday, 19 February 1999
Clinical
Scenario: A patient with carcinoma of the
cervix presented for radiotherapy. We wondered if irradiation while having
hyperbaric oxygen would result in improved tumour control or survival.
Three-part
Question: In patients with carcinoma of
the cervix who present for radiotherapy, does the conduct of radiotherapy while
in hyperbaric oxygen, compared to irradiation in air, result in any improvement
in local or distant tumour control, or survival?
Search
Terms: Hyperbaric oxygenation, tumour/cervix
The
Study:
Non-blinded randomised
controlled trial without intention-to-treat. Patients with stage IIB to IVA
cervical cancer presenting for radiotherapy at one of four treatment centres.
Control group (N = 29; 29
analysed): 5,000 rads total dose over 5 weeks with 25 fractions (1,530 rets) in
air. Intracavitary irradiation where possible.
Experimental group (N = 29; 29
analysed): 4,000 rads over 5 weeks with 10 fractions (1,524 rets) in oxygen at
3ATA for up to 45 minutes. Intracavitary irradiation where possible.
The
Evidence:
|
Outcome |
Time to
Outcome |
Air group |
HBO group |
Relative
risk increase |
Absolute
risk increase |
NNH |
|
Death |
4 years |
0.59 |
0.62 |
5% |
0.03 |
33 |
|
95% CI: |
|
|
|
-38% to 48% |
-0.22 to 0.28 |
NNH=4 to INF
NNT=5 to INF |
|
Local
recurrence |
4 years |
0.276 |
0.345 |
25% |
0.07 |
-14 |
|
95% CI: |
|
|
|
61% to 100% |
-0.17 to 0.31 |
NNH=3 to INF
NNT=6 to INF |
|
Treatment
complications and no tumour |
4 years |
0.069 |
0.172 |
149% |
0.10 |
-10 |
|
95% CI: |
|
|
|
-91% to ?% |
-0.06 to 0.27 |
NNH=4 to INF
NNT=16 to INF |
Comments:
1. Small trial in which 10/29
patients randomised to hyperbaric oxygen did not receive it.
2. Trends to lower rate of local
recurrence and higher rate of treatment complications in the hyperbaric oxygen
group when not analysed by intention to treat.
Expiry
date:
January 2004
References:
1.Brady LW, Plenk HP, Hanley JA,
Glassburn JR, Kramer S, Parker RG. Hyperbaric oxygen therapy for carcinoma of
the cervix- stages IIB, IIIA, IIIB and IVA: results of a randomised study by the
radiation therapy oncology group. International Journal of Radiation Oncology,
Biology and Physics 1981;7:991-998.
