-methylthiosemicarbazone)(Cu-ATSM) to image hypoxia. Another direct approach to prove and measurehypoxia in tumours was first taken with oxygen electrodes (missing citation).However the procedure is not feasible for radiotherapy treatment planning.Although it is difficult to prove the quantitative validity of the FMISO andCu-ATSM SUVs there is an abundance of research showing promising results foradaptive radiotherapy based on these uptakes as biomarkers for hypoxia. Inaddition to hypoxia imaging at baseline temporal changes in oxygenation mighthave substantial influence on the TCP. A second or even third PET image aftercertain periods of treatment time might be reasonable (missing citation). Asidefrom FMISO and Cu-ATSM there are other possible tracers such as FAZA FETNIMEF5 or EF3. Their differences in uptake characteristics and in hypoxialocalisation are of special interest and need to be further investigated inspite of (or actually even due to) the possibility of a lack in co-localisationand boost-volume definition.