Hyperbaric
oxygenation was associated with improved survival and possibly local recurrence
rate following irradiation of tumours of the head and neck.
Clinical Bottom Line:
1.
There was a significant increase in five year survival when this dosage regime
of radiotherapy was given while having hyperbaric oxygenation.
2.
There was some evidence of an improvement in local recurrence rate with
hyperbaric oxygen.
Appraised
by: Mike
Bennett, Dept of Diving and Hyperbaric Medicine, Prince of Wales Hospital,
Sydney; Sunday, 28 February 1999
Clinical
Scenario:
A patient presented with oral cancer for radiotherapy. We wondered if
performing the radiotherapy while breathing hyperbaric oxygen would improve
outcome.
Three-part
Question: In patients with head and neck
squamous cell carcinoma, does the administration of hyperbaric oxygen during
radiotherapy, compared to breathing air, result in an improved survival or local
control rate?
Search
Terms: Hyperbaric oxygenation, tumours/head
and neck
The
Study:
Non-blinded concealed randomised
controlled trial with intention-to-treat.
Patients with SCC of the mouth,
upper airway or middle ear where the therapeutic treatment of choice was
radiotherapy.
Control group (N = 52; 52
analysed): 30 equal fractions of radiotherapy over 6 weeks to a total dose of
6,500rads (1875rets).
Experimental group (N = 51; 51
analysed): 10 equal fractions over 22 days to a dose of 4,100 rads (1875 rets).
Different dosing regime but equivalent nominal standard dose except when the
larynx was irradiated (10% reduction). Oxygen dose not given.
The
Evidence:
|
Outcome |
Time
to Outcome |
Air
group |
HBO
rate |
Relative
risk reduction |
Absolute
risk reduction |
NNT |
|
Survival |
4
years |
.27 |
.56 |
107% |
0.290 |
3 |
|
95%
CI: |
|
|
|
40%
to 100% |
0.108
to 0.472 |
2
to 9 |
|
Recurrence
free |
4
years |
.40 |
.61 |
53% |
0.210 |
5 |
|
95%
CI: |
|
|
|
5%
to 100% |
0.021
to 0.399 |
3
to 47 |
Comments:
1.Full figures for
survival/recurrence not given, making the table above unreliable.
2.This trial follows the earlier
study by same workers. Dose regime changed for this trial to compare usual
therapy against a small fraction therapy for the air group.
3.Relevance to today's practice
of these findings may be slight.
4.Authors comment that the
therapy is difficult and time consuming.
Expiry date: January 2004
References:1.Henk
JM, Smith CW. Radiotherapy and hyperbaric oxygen in head and neck cancer.
Interim report of second clinical trial. Lancet 1977; 8014:104-105.
2. Henk JM. Late results of a
trial of hyperbaric oxygen and radiotherapy in head and neck cancer: a rationale
for hypoxic cell sensitizers? International Journal of Radiation Oncology,
Biology and Physics 1986; 12:1339-1341.
3. Henk JM. Overcoming the
oxygen effect: hyperbaric oxygen or protracted fractionation. Fifth
International Hyperbaric Congress Proceedings II 1974:794-801.
4. Henk JM. The influence of oxygen and hypoxia on laryngeal cancer management. Laryngoscope 1975;85:1134-1144.
