The age of reason for FDG PET image-derived indices

The clinical use of Positron Emission Tomography (PET) imaging using the 2-deoxy-2-(18F)fluoro-D-glucose (18F-FDG) is currently predominantly focused on diagnostic purposes within the field of oncology. Within this context, image analysis is largely based on visual interpretation and the use of simple image derived indices, such as the maximum standardised uptake value (SUVmax), which corresponds to the voxel with the maximum activity concentration within the tumour scaled by the administered activity, patient weight and blood glucose concentration. On the other hand, during the last few years there has been increasing interest in the use of 18F-FDG PET imaging for the prediction and monitoring of therapy response. Within this context the SUVmax has been also predominantly used, where differences between a pre-treatment and post-treatment scan have been shown to closely correlate with clinical response to treatment for a number of different cancer models [1,2].