The viability of DCE-CT kinetic analysis in tumor vasculature imaging in veterinary medicine

Tumor vasculature imaging plays an important role in oncology. Dynamic contrast-enhanced computed tomography (DCE-CT) is a non-invasive method for imaging tumor vasculature. However, in order to be useful in veterinary clinical oncology, DCE-CT imaging needs to provide quantitatively precise and accurate vasculature parameters. The overall goal of this work was to investigate the viability of DCE-CT kinetic analysis in tumor vasculature imaging in veterinary patients.;To assess the precision of kinetic parameters derived from DCE-CT imaging, we implemented kinetic models and characterized uncertainties impacting the quantitative accuracy and precision of the kinetic parameters in veterinary scans. These factors originated from the CT scanner, the analysis, and the patient, including minimally researched factors, such as vessel selection, vessel segmentation, acquisition time, and patient-specific effects. We found that the kinetic parameters were sensitive to many sources of error leading to an overall high level of uncertainty.;In order to validate the results of DCE-CT scans in veterinary patients, we compared DCE-CT kinetic parameters to FLT-PET kinetic parameters. We found moderate agreement between kinetic parameters from the two imaging modalities on the voxel-level. However, kinetic parameter uncertainties on the voxel-level strongly impacted the agreement as the application of noise reduction techniques improved agreement between the imaging modalities.;In order to assess the added value of DCE-CT scans in multi-modality imaging in veterinary patients, we compared DCE-CT kinetic parameters to pre-treatment PET tracer uptake values and responses to radiation therapy. PET tracers were used to image glucose metabolism (FDG), cellular proliferation (FLT), and hypoxia (Cu-ATSM). Poor voxel-based agreement was found between tracer uptake patterns and DCE-CT kinetic parameters, but moderate agreement was found between patients using whole-tumor analysis. Similar trends were observed between the responses of the DCE-CT kinetic parameters and tracer uptake to radiation therapy for both voxel-based and whole-tumor analyses.;In conclusion, DCE-CT kinetic analysis requires further improvements in order to increase its utility in tumor vascular imaging for veterinary patients. DCE-CT kinetic parameters are sensitive to several sources of uncertainty. Current applications of DCE-CT kinetic analysis should attempt to minimize noise and use only whole-tumor analysis, and not voxel-based analysis.