title: Tumour oxygenation levels correlate with dynamic contrast-enhanced magnetic resonance imaging parameters in carcinoma of the cervix.
abstract: 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.
authors.affiliation: CRC Experimental Radiation Oncology Group, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, M20 4BX, Manchester, UK.
authors.forename: R A
authors.initials: RA
authors.lastname: Cooper
authors.forename: B M
authors.initials: BM
authors.lastname: Carrington
authors.forename: J A
authors.initials: JA
authors.lastname: Loncaster
authors.forename: S M
authors.initials: SM
authors.lastname: Todd
authors.forename: S E
authors.initials: SE
authors.lastname: Davidson
authors.forename: J P
authors.initials: JP
authors.lastname: Logue
authors.forename: A D
authors.initials: AD
authors.lastname: Luthra
authors.forename: A P
authors.initials: AP
authors.lastname: Jones
authors.forename: I
authors.initials: I
authors.lastname: Stratford
authors.forename: R D
authors.initials: RD
authors.lastname: Hunter
authors.forename: C M
authors.initials: CM
authors.lastname: West
mesh_terms: 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
chemical_list: D003287:Contrast Media; D005682:Gadolinium; D010100:Oxygen