Tumour oxygenation levels correlate with dynamic contrast-enhanced magnetic resonance imaging parameters in carcinoma of the cervix.
OBJECTIVE
The Eppendorf pO(2) histograph is the 'gold standard' method for measuring tumour oxygenation. The method is not suitable for widespread application because its use is limited to accessible tumours. A non-invasive imaging technique would be an attractive alternative. Therefore, the relationships between tumour oxygenation and dynamic contrast-enhanced magnetic resonance imaging (MRI) parameters were investigated.


METHODS
The study comprised 30 patients with carcinoma of the cervix. Tumour oxygenation was measured pre-treatment as median pO(2) and the proportion of values less than 5 mmHg (HP5) using a pO(2) histograph. Repeat measurements were obtained for nine patients following 40-45 Gy external beam radiotherapy giving a total of 39 measurements. Dynamic contrast-enhanced MRI using gadolinium was performed prior to obtaining the oxygenation data. Time/signal intensity curves were generated to obtain two standard parameters: maximum enhancement over baseline (SI-I) and the rate of enhancement (SI-I/s).


RESULTS
Using the 39 measurements, there was a significant correlation between SI-I and both median pO(2) (r=0.59; P<0.001) and HP5 (r=-0. 49; P=0.002). There was a weak, borderline significant correlation between SI-I/s and both median pO(2) (r=0.29; P=0.071) and HP5 (r=-0. 34; P=0.037). There was a significant relationship between tumour size and SI-I (r=0.54; P<0.001), but not SI-I/s. In 29 tumours, where data were available, there was no relationship between histological assessment of tumour angiogenesis (intra-tumour microvessel density; IMD) and either MRI parameter.


CONCLUSIONS
Tumour oxygenation levels measured using a pO(2) histograph correlate with dynamic contrast-enhanced MRI parameters. Therefore, non-invasive dynamic MRI may be a method for measuring hypoxia in human tumours.
Cooper
R A
RA
CRC Experimental Radiation Oncology Group, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, M20 4BX, Manchester, UK.
Carrington
B M
BM
Loncaster
J A
JA
Todd
S M
SM
Davidson
S E
SE
Logue
J P
JP
Luthra
A D
AD
Jones
A P
AP
Stratford
I
I
Hunter
R D
RD
West
C M
CM
D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000098:blood supply* / Q000175:diagnosis*; D002584:Cervix Uteri / Q000098:blood supply* / Q000378:metabolism; D003287:Contrast Media; D005260:Female; D005682:Gadolinium; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000175:diagnosis; D010100:Oxygen / Q000032:analysis* / Q000378:metabolism; D010101:Oxygen Consumption; D011379:Prognosis; D011856:Radiographic Image Enhancement; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D002583:Uterine Cervical Neoplasms / Q000098:blood supply* / Q000175:diagnosis* / Q000532:radiotherapy
D003287:Contrast Media; D005682:Gadolinium; D010100:Oxygen