Carbogen inhalation in cervical cancer: assessment of oxygenation change.
OBJECTIVE
Our objectives were (1) to examine tumor oxygenation measured with an Eppendorf pO(2) histograph, prior to and during carbogen (95% oxygen, 5% carbon dioxide) breathing in patients with primary cervical cancer; and (2) to assess the feasibility of delivering external beam radiation therapy and concurrent carbogen to patients treated for cervical cancer.


METHODS
Pretreatment tumoral pO(2) measurements were obtained using an Eppendorf pO(2) histograph in patients with primary cervical cancers while breathing room air and after 4 min of carbogen breathing. Patients able to tolerate the carbogen inhalation were asked to inhale it for 4 min prior to and during all external beam radiation therapy.


RESULTS
Two sets of pO(2) measurements were obtained from 25 patients. The average median pO(2) increased from 8 mm Hg when breathing room air to 96 mm Hg after carbogen breathing. Twenty-four of 25 patients tolerated the carbogen; they inhaled carbogen during their daily external beam radiation therapy. All 24 patients completed their planned course of external beam radiation therapy and daily concurrent carbogen without significant difficulty.


CONCLUSIONS
(1) Carbogen inhalation increased the average median pO(2) value 10-fold and decreased the percentage of values </=2.5 and 5 mm Hg. (2) Carbogen inhalation is feasible during external beam pelvic radiation.
Aquino-Parsons
C
C
Department of Surgery, University Health Sciences Centre Hospital, Radiation Oncology, British Columbia Cancer Agency, Canada.
Lim
P
P
Green
A
A
Minchinton
A I
AI
D000280:Administration, Inhalation; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002245:Carbon Dioxide / Q000008:administration & dosage*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D010100:Oxygen / Q000008:administration & dosage* / Q000378:metabolism*; D011838:Radiation-Sensitizing Agents / Q000008:administration & dosage*; D002583:Uterine Cervical Neoplasms / Q000378:metabolism* / Q000532:radiotherapy*
D011838:Radiation-Sensitizing Agents; D002245:Carbon Dioxide; C011700:carbogen; D010100:Oxygen