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.