Blood flow-metabolic relationships are dependent on tumour size in non-small cell lung cancer: a study using quantitative contrast-enhanced computer tomography and positron emission tomography.
OBJECTIVE
The purpose of this study was to undertake dual assessment of tumour blood flow and glucose metabolism in non-small cell lung cancer (NSCLC) using contrast-enhanced computed tomography (CE-CT) and (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) in order to assess how the relationships between these parameters vary with tumour size and stage.


METHODS
Tumour blood flow and glucose metabolism were assessed in 18 NSCLCs using quantitative CE-CT and FDG-PET respectively. Contrast enhancement and FDG uptake were both normalised to injected dose and patient weight to yield correspondingly the standardised perfusion value (SPV) and standardised uptake value (SUV). Tumour area was measured from conventional CT images.


RESULTS
The ratio of SUV to SVP and the metabolic-flow difference (SUV-SVP) correlated with tumour size (r=0.56, p=0.015 and r=0.60 and p=0.008 respectively). A metabolic-flow difference of greater than 4 was more common amongst tumours of stages III and IV (odds ratio 10.5; 95% confidence limits 0.24-32.1). A significant correlation between SUV and SPV was found only for tumours smaller than 4.5 cm2 (r=0.85, p=0.03).


CONCLUSIONS
Blood flow-metabolic relationships are not consistent in NSCLC but depend upon tumour size and stage. Quantitative CE-CT as an adjunct to an FDG study undertaken using integrated PET-CT offers an efficient way to augment the assessment of tumour biology with possible future application as part of clinical care.
Miles
K A
KA
Division of Clinical and Laboratory Sciences, Brighton & Sussex Medical School, University of Sussex, Brighton, BN7 3PB, UK. k.a.miles@bsms.ac.uk
Griffiths
M R
MR
Keith
C J
CJ
D001783:Blood Flow Velocity; D003287:Contrast Media; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008175:Lung Neoplasms / Q000098:blood supply* / Q000150:complications / Q000000981:diagnostic imaging / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000150:complications / Q000000981:diagnostic imaging / Q000378:metabolism*; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013223:Statistics as Topic; D014057:Tomography, X-Ray Computed / Q000379:methods*
D003287:Contrast Media; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D005947:Glucose