Comparison of methodologies for the in vivo assessment of 18FLT utilisation in colorectal cancer

摘要: Fluorine-18 3-deoxy-3-fluorothymidine (18FLT) is a tissue proliferation marker which has been suggested as new tumour-specific imaging tracer in positron emission tomography (PET). The objectives of this study were to investigate the pharmacokinetics 18FLT patients with colorectal cancer, defining methodologies for quantitative analysis vivo uptake and subsequently assessing accuracy semi-quantitative measures. Dynamic acquisitions over single field view interest identified by computed carried out up 60 min following injection (360±25 MBq). arterial blood sampling was order provide input function. Simultaneous venous samples also taken their potential utilisation deriving hybrid Arterial at 5, 15, 30, 90 p.i. used metabolite analysis. Eleven primary and/or metastatic cancer studied on lesion basis (n=21). All acquired images reconstructed using ordered subsets expectation maximisation segmented attenuation correction. Time-activity curves derived image region (ROI) image-based functions obtained abdominal or thoracic aorta ROIs. Standardised values (SUVs) calculated indices uptake, while non-linear regression (NLR) methodology association three-compartment model Patlak derive net influx constant K i . revealed two radioactive metabolites, parent compound representing ~80% total radioactivity 30-min plasma sample. In case NLR, better fits 3k (i.e. k 4=0) both bone marrow time-activity curves. For same lesions, high correlation observed between from either NLR(3k) corresponding SUVs. Our results suggest that behaviour (up p.i.) may be characterised combination image-derived functions. good found SUVs (at min) supports use assess rate lesions 18FLT.