Preclinical Testing of Novel Radiotracers for Positron Emission Tomography (PET)

Preclinical tests of novel radiotracers in experimental animals are required tomove tracer candidates from the stage of in vitro testing to the stage of toxicitytesting and finally studies in human volunteers. Such preclinical tests are aimedat demonstrating: (1) specific in vivo interaction of the tracer with its target,(2) adequate kinetics and metabolic stability of the tracer after it has beeninjected into living mammals, and (3) sensitivity of tracer uptake to changesof target expression. Possible strategies to reach these aims are discussed,including specific animal models which are used in our institution. Theseinclude pharmacological treatment of healthy animals, target gene knockout,tumor growth, brain lesions resulting in loss of myelin, viral infection, sterileinflammation, and xenografting of inflammatory cells