I059] Working in radiotherapy from the perspective of a nuclear medicine physicist

Abstract

Accurate and reliable PET/CT imaging is mandatory when performing quantitative assessment of radiotracer (FDG) uptake. This becomes even more important when PET is used in a radiotherapy (RTR) setting, either for assessment of target lesions, tumour delineation or response prediction and assessment. Moreover, there are specific requirements with respect to the imaging procedure when FDG PET/CT is used in a radiotherapy setting, such as e.g. the needs for a flat table, immobilisation devices equal to those used at radiotherapy and use of lasers for patient positioning. A specific challenge when PET is used for radiotherapy purposes is the exchange of knowledge and methodology between the nuclear medicine (NM) and radiotherapy physics disciplines. Often NM physicists are not aware of the specific RT requirements and applications, while RT physicists are not aware of the specific requirements for performing reliable PET imaging. In this presentation, requirements for reliable quantitative FDG PET/CT imaging from the NM physics perspective will be addressed. Technical and imaging physics related factors that affect PET image quality will be discussed as well as the need for standardizing imaging procedures and performing dedicated quality control procedures to assure harmonized performance (between systems and longitudinally). Finally, the impact of new PET/CT technologies, such as use of resolution modelling during reconstruction and digital PET detectors, on image quality and quantification and their relevance for RT applications will be reviewed.