Irradiation
of head and neck squamous cell carcinomas while breathing hyperbaric oxygen was
not associated with improved outcomes.
Clinical Bottom Line:
1.
The two regimes tested produced comparable survival, local control of tumour
and complication rates.
Appraised
by: Mike Bennett, Dept of Diving and
Hyperbaric Medicine, Prince of Wales Hospital
Sydney; Thursday, 18 February,
1999
Clinical
Scenario: A patient with a squamous cell
carcinoma (SCC) of the tongue presented for radiotherapy.
Three-part
Question: In treatment of SCC of the head
and neck, does irradiation in a hyperbaric oxygen chamber, compared to in air,
result in improved survival or fewer side-effects?
Search
Terms: Hyperbaric oxygenation, tumour/head
and neck
The
Study:
Non-blinded randomised
controlled trial with intention-to-treat.
Patients with SCCs of the head
and neck referred for radiotherapy.
Control group (N = 23; 23
analysed): Radiotherapy four days each week for approximately six weeks, to a
total dose of 6,250 rads in air.
Experimental group (N = 21; 21
analysed): Radiotherapy 2.5 times each week for approximately five weeks to
4,800 rads total dose while breathing oxygen at three atmospheres. Ret dose
slightly lower than air group.
The
Evidence:
|
Outcome |
Time
to Outcome |
Air
group |
HBO
group |
Relative
risk reduction |
Absolute
risk reduction |
NNT |
|
Local
recurrence |
2
years |
0.44 |
0.38 |
12% |
0.05 |
19 |
|
95%
CI: |
|
|
|
-54%
to 79% |
-0.24
to 0.34 |
NNT=3
to INF NNH=4 to
INF |
|
Death |
2
years |
0.48 |
0.43 |
9% |
0.05 |
20 |
|
95%
CI: |
|
|
|
-47%
to 66% |
-0.25
to 0.34 |
NNT=3
to INF NNH=4 to
INF |
|
Treatment
complications |
2
years |
0.217 |
0.190 |
12% |
0.03 |
37 |
|
95%
CI: |
|
|
|
-97%
to 100% |
-0.21
to 0.27 |
NNT=4
to INF NNH=5 to
INF |
Comments:
1. Six patients were excluded
after randomisation, 5 because of early death from intercurrent disease.
2. Treatment tested was HBO and
a shorter radiotherapy regime with fewer fractions.
3. Relevance to practice today
is unclear.
Expiry
date:
January 2004
References:
1. Sause WT, Plenk HP. Radiation therapy of head and neck
tumours: a randomised study of treatment in air vs. treatment in hyperbaric
oxygen. International Journal of Radiation Oncology, Biology and Physics 1979;
5:1833-1836.
