2.2.2 MeAIB. α-(N-methyl-11C)-methylaminobutyric acid (MeAIB) is an amino acid analog that concentrates into cells only via the System A amino acid transport system, which has been shown to be highly upregulated in malignant cells making it a potential target for oncological imaging . The tracer has been developed by our local chief radiochemist and studies on biodistribution and dosimetry conclude that MeAIB is a tracer usable in humans with radiation doses lower than other used PET-tracers , . Clinical studies on the use of MeAIB-PET/CT in oncology are sparse , . The use of MeAIB-PET/CT in PCa has not been investigated. Unpublished data suggests that MeAIB could prove useful in diagnosing PCa because of a high uptake in prostatic tumors . Due to the short half-life of 11C (20 min.) an onsite cyclotron is required for performing the study, and thus this is possible in Odense.