Cervix cancer oxygenation measured following external radiation therapy.
OBJECTIVE
Tumor hypoxia may be an important factor predicting relapse following radiation therapy. This study was designed to determine the relationship between the oxygenation parameters measured using a polarographic oxygen electrode, prior to and during treatment in patients with cervix cancer, and to assess these results with regard to patient survival.


METHODS
Forty-three patients had pretreatment oxygen assays performed and measurements repeated following external beam radiation to a median dose of 50 Gy (range 26-52 Gy). Stage distribution showed 15 patients in Stage IB, 17 in Stage II, and 11 in Stage III. The median tumor size was 5 cm (range 3-10 cm).


RESULTS
The median proportion of pO2 values <5 mm Hg (the HP5) was 41% following radiation, and the median pO2 was 12 mm Hg. These results were not significantly different from the pretreatment HP5 or pO2 of 37% and 12 mm Hg, respectively. Disease-free survival at 2 years was 50% in patients with posttreatment HP5 < or =50%, compared to 60% when posttreatment HP5 was >50% (p = 0.35).


CONCLUSIONS
Unlike pretreatment results, tumour oxygenation measured following external radiation does not appear to be a useful predictive assay in patients with cervical cancer.
Fyles
A W
AW
Department of Radiation Oncology, Ontario Cancer Institute/Princess Margaret Hospital, University of Toronto, Canada.
Milosevic
M
M
Pintilie
M
M
Hill
R P
RP
D000328:Adult; D000368:Aged; D015687:Cell Hypoxia; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D010101:Oxygen Consumption; D010313:Partial Pressure; D016896:Treatment Outcome; D002583:Uterine Cervical Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000532:radiotherapy*