F-Fluordesoxyglucose(FDG) PET. In addition to its high signal-to-noise ratio further advantages ofFDG are its easy availability and its common use in clinical routine andresearch. Many departments already gathered the extensive experience requiredto make FDG uptake a feasible and reliable biomarker (missing citation);(missing citation); (missing citation); (missing citation). However thestandardized uptake value (SUV) is not solely dependent on clonogen density butalso on other factors such as tumour perfusion rate of glycolysisproliferation inflammation and hypoxia (missing citation); (missing citation).So far there is only limited data available on alternative tracers such asamino-acids (e.g. MET) (missing citation) fluoroethyl-L-tyrosine (FET) or