Improvement in human tumour oxygenation with carbogen of varying carbon dioxide concentrations.
OBJECTIVE
Carbogen (95%O2, 5%CO2) is being used in clinical trials as a hypoxic radiosensitiser. Tolerance to carbogen can be a problem, this study compares tumour oxygenation during inhalation of hyperoxic gas containing either 2% or 5% CO2.


METHODS
Tumour pO2 was measured in 16 patients using the Eppendorf pO2 histograph.


RESULTS
After breathing gas containing either 5% or 2% CO2 an increase in median pO2 was measured in every tumour, the frequency of low pO2 values ( < or = 10 mmHg) fell from 47% to 29% in the 5% group and from 55% to 17% in the 2% group.


CONCLUSIONS
This study confirms that breathing 2% CO2 and 98% O2 is well tolerated and effective in increasing tumour oxygenation.
Powell
M E
ME
CRC Tumour Biology and Radiation Research Group, Mount Vernon Hospital, Northwood, Middlesex, UK.
Collingridge
D R
DR
Saunders
M I
MI
Hoskin
P J
PJ
Hill
S A
SA
Chaplin
D J
DJ
D000280:Administration, Inhalation; D002245:Carbon Dioxide / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D009369:Neoplasms / Q000378:metabolism* / Q000532:radiotherapy; D010100:Oxygen / Q000008:administration & dosage* / Q000378:metabolism*; D011838:Radiation-Sensitizing Agents / Q000008:administration & dosage*; D016896:Treatment Outcome
D011838:Radiation-Sensitizing Agents; D002245:Carbon Dioxide; C011700:carbogen; D010100:Oxygen