Personalized medicine employing patient-based tailor-made therapeutic drugs is taking over treatment paradigms in a variety of ?elds in oncology and the central nervous system. The success of such therapies is mainly dependent on ef?cacious therapeutic drugs and a selective imaging probe for identi?cation of potential responders as well as therapy monitoring for an early bene?t assessment. Molecular imaging (MI) is based on the selective and speci?c interaction of a molecular probe with a biological target which is visualized through nuclear, magnetic resonance, near infrared or other methods. Therefore it is the method of choice for patient selection and therapy monitoring as well as for speci?c e- point monitoring in modern drug development. PET (positron emitting tomography), a nuclear medical imaging modality, is ideally suited to produce three-dimensional images of various targets or processes. The rapidly increasing demand for highly selective probes for MI strongly pushes the development of new PET tracers and PET chemistry. ‘PET chemistry’ can be de?ned as the study of positron-emitting compounds regarding their synthesis, structure, composition, reactivity, nuclear properties and processes and their properties in natural and - natural environments. In practice PET chemistry is strongly in?uenced by the unique properties of the radioisotopes used (e. g. , half-life, che- cal reactivity, etc. ) and integrates scienti?c aspects of nuclear-, organic-, inorganic- and biochemistry.

Marking the 200th National Meeting of the American Chemical Society, The Division of Nuclear Chemistry and Technology hosted a group of about 90 scientists from 15 different countries to discuss the new trends in radiopharmaceutical synthesis, quality assurance and regulatory control. This event took place in Washington, D.C. on August 27-30, 1990. When I first suggested the idea for this symposium, a group of scientists who pioneered the proposed topics offered their help to organize and run such a big task with me. Their names are listed here in appreciation. Thomas E. Boothe Cyclotron Facility, Mt. Sinai Medical Center, Miami Beach, Florida, USA Robert F. Dannals Division of Nuclear Medicine, The Johns Hopkins Medical Institutions, Baltimore, Maryland, USA Anthony L. Feliu Julich Nuclear Research Center, Julich, Germany Joanna S. Fowler Chemistry Department, Brookhaven National Laboratory, Upton, New York, USA George W. Kabalka Department of Chemistry, University of Tennessee, Knoxville, Tennessee, USA Hank F. Kung Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA James F. Lamb Imagents, Inc., Houston, Texas, USA Harold A. O'Brien, Jr. Los Alamos National Laboratory, Los Alamos, New Mexico, USA Joseph R. Peterson Dept. of Chemistry, University of Tennessee, Knoxville, Tennessee, USA Hernan Vera Ruiz International Atomic Energy Agency, Vienna, Austria Roy S. Tilbury University of Texas, M. D. Anderson Cancer Center, Houston, Texas, USA In addition, a number of distinguished colleagues have participated in the process of reviewing the manuscripts presented in this volume. Their effort is sincerely acknowledged.