Radiophannaceuticals labeled with short-lived radionuclides are utilized
to unravel biochemical processes, and to diagnosis and treat diseases of
the living body are-developed through extensive evaluation in iological
models. 'fhC first attempt to compile information was a volume entitled
ANIMAL MODELS IN RADIOTRACER DESIGN that was edited by William C.
Eckelman and myself in 1983. The volume had a focus on the animal models
that investigators were using in order to design radiotracers that
displayed in vivo selectivity as measured by biodistribution and
pharmacokinetic studies. A concern in the early days of nuclear medicine
was species differences. Often a series of labeled compounds were
evaluated in a several different animal models in order to gain
confidence that the selected radiotracer would behave appropriately in
humans. During the past 12 years there have been remarkable advances in
molecular genetics, molecular biology, synthetic radiopharmaceutical
chemistry, molecular modeling and visualization, and emission
tomography. Biological models can now be selected that are better
defined in terms of molecular aspects of the disease process. The
development of high resolution PET and SPET for clinical applications
facilitates the development of new radiopharmaceuticals by the use of
models to quantitatively evaluate drug effects, and progression of
disease, and hence to arrive at better diagnosis and treatments for
animals and humans. With these advances there is an effective use of
biological models, and the refinement of alternatives for the
development of new radiophannaceuticals.