ABSTRACT
Abstract The aim of this study was to evaluate if hypoxia in feline fibrosarcomas can be detected. This was done using positron emission tomography (PET), two hypoxia tracers and polarographic pO(2) measurements. Of the seven cats included, five received [(18)F]-fluoromisonidazole and two 2-(2-nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl) acetamide. Perfusion was evaluated with [(15)O]-H(2)O (n = 4) and with contrast-enhanced power Doppler ultrasonography (n = 5). Hypoxia was detected in three cats. Polarographic pO(2) measurements did not confirm PET results. In the ultrasonographic evaluation, low vascularity and low perfusion were seen with a peripheral vascular pattern and no perfusion in the centre of the tumour. This was in contrast to the [(15)O]-H(2)O scans, where central perfusion of the tumour was also found. In conclusion, it appears that hypoxia exists in this tumour type. The presence of tumour necrosis and heterogeneous hypoxia patterns in these tumours may explain the found discrepancies between the applied techniques.
ABSTRACT
In human medicine positron emission tomography (PET) is a modern diagnostic imaging method. In the present paper we outline the physical principles of PET and give an overview over the main clinic fields where PET is being used, such as neurology, cardiology and oncology. Moreover, we present a current project in veterinary medicine (in collaboration with the Paul Scherrer Institute and the University Hospital Zurich), where a hypoxia tracer is applied to dogs and cats suffering from spontaneous tumors. Finally new developments in the field of PET were discussed.
