Radiophannaceutical research has recently undergone a major change in direction. In past years it has been concerned mainly with the development of perfusion tracers, the biodistribution of which reflect the regional blood flow to areas of major organs such as the heart and brain. However, a major new direction of interest now lies in the development of receptor-binding radio-tracers which can be used to perform in-vivo characterisation of diseased tissues and it is likely that much of the future research in this field will follow this direction. The difficulties in developing such tracers are considerable. The researcher must first identify a promising target for radiopharmaceutical development. High specific activity radioactive molecules must be designed and synthesised which will both bind to the target receptor with high affinity, and also have the physicochemical characteristics which will allow them to reach the target site in sufficient quantity while at the same time showing minimal uptake in non-target tissues. Thus the knowledge base required for radiophannaceutical development has now expanded beyond the limits of radiopharmaceutical chemistry to include aspects of biochemistry, molecular biology and conventional drug design. The portfolio of basic knowledge required to support current radiopharmaceutical development is changing and scientists working in this arena need to be trained in this regard. At the same time, the very latest developments in the field need to be communicated to the scientific community in order to stimulate the advancement of this exciting new direction of research.

The contents of this volume are based upon presentations made to the Second European Symposium on Radiopharmacy and Radiopharmaceuticals which was held in St. Catharine's College Cambridge in March 1985. This meeting was organized by the Radiopharmacy Group of the British Nuclear Medicine Society under the auspices of the European Joint Committee on Radio pharmaceuticals of the ENMS / SNME. The Joint Committee acknowledges the special effort which was made by the local organizers to prepare this meeting the quality of which is undoubtedly reflected in the proceedings. The wide ranging aspects of Radiopharmacy are reflected in this volume which not only deals with specialized topics, such as aerosols and biodistribution studies, but which also deals with the professional aspects of Radiopharmacy Practice. We are of the opinion that this book complements earlier publications to give an ongoing picture of the practice of Radiopharmacy and the state of the art in Europe. As well as acknowledging the contribution of the British Radiopharmacists I would also mention the support of my co chairman Prof. Dr M.G. Woldring, the members of the Joint Committee and last but not least Mrs. M. Busker, who prepared the camera ready copy. P.H. Cox Co-ordinating Chairman European Joint Committee on Radiopharmaceuticals Rotterdam XI CCNrRIBUTORS Anderson, M.L. - Pharnacy department, London Hospital London, UK. Angelberger, P. - Osterreichische Forschungszentrum Seibersdorf GmbH, Wien, Austria. Claessens, R.A.M.J. - Department of Nuclear Medicine, St. Radboud Ziekenhuis, Nijrnegen, The Netherlands."

The contents of this volume are based upon presentations made to the Second European Symposium on Radiopharmacy and Radiopharmaceuticals which was held in St. Catharine's College Cambridge in March 1985. This meeting was organized by the Radiopharmacy Group of the British Nuclear Medicine Society under the auspices of the European Joint Committee on Radio pharmaceuticals of the ENMS / SNME. The Joint Committee acknowledges the special effort which was made by the local organizers to prepare this meeting the quality of which is undoubtedly reflected in the proceedings. The wide ranging aspects of Radiopharmacy are reflected in this volume which not only deals with specialized topics, such as aerosols and biodistribution studies, but which also deals with the professional aspects of Radiopharmacy Practice. We are of the opinion that this book complements earlier publications to give an ongoing picture of the practice of Radiopharmacy and the state of the art in Europe. As well as acknowledging the contribution of the British Radiopharmacists I would also mention the support of my co chairman Prof. Dr M.G. Woldring, the members of the Joint Committee and last but not least Mrs. M. Busker, who prepared the camera ready copy. P.H. Cox Co-ordinating Chairman European Joint Committee on Radiopharmaceuticals Rotterdam XI CCNrRIBUTORS Anderson, M.L. - Pharnacy department, London Hospital London, UK. Angelberger, P. - Osterreichische Forschungszentrum Seibersdorf GmbH, Wien, Austria. Claessens, R.A.M.J. - Department of Nuclear Medicine, St. Radboud Ziekenhuis, Nijrnegen, The Netherlands."

Radiophannaceutical research has recently undergone a major change in direction. In past years it has been concerned mainly with the development of perfusion tracers, the biodistribution of which reflect the regional blood flow to areas of major organs such as the heart and brain. However, a major new direction of interest now lies in the development of receptor-binding radio-tracers which can be used to perform in-vivo characterisation of diseased tissues and it is likely that much of the future research in this field will follow this direction. The difficulties in developing such tracers are considerable. The researcher must first identify a promising target for radiopharmaceutical development. High specific activity radioactive molecules must be designed and synthesised which will both bind to the target receptor with high affinity, and also have the physicochemical characteristics which will allow them to reach the target site in sufficient quantity while at the same time showing minimal uptake in non-target tissues. Thus the knowledge base required for radiophannaceutical development has now expanded beyond the limits of radiopharmaceutical chemistry to include aspects of biochemistry, molecular biology and conventional drug design. The portfolio of basic knowledge required to support current radiopharmaceutical development is changing and scientists working in this arena need to be trained in this regard. At the same time, the very latest developments in the field need to be communicated to the scientific community in order to stimulate the advancement of this exciting new direction of research.