Future trends in the application of radionuclides in diagnostic and therapeutic nuclear medicine
Habib ZAIDI, Ph.D, PD
Geneva University Hospital
Division of Nuclear Medicine, CH-1211 Geneva, Switzerland
Phone: + 41 22 372 72 58
Fax: + 41 22 372 71 69
Abstract. The use of radionuclides in medicine has a long history and encompasses a large area of applications including diagnosis and radiation treatment of cancer patients using either external or radionuclide radiotherapy. Nuclear medicine uses different kinds of nonencapsulated (in liquid or gaseous form) isotopes that are administered to patients to perform morphological and functional studies of different organs and radioanalytical determinations of numerous substances contained in the organism. In addition to this, ionizing radiation from radioactive isotopes is extensively used in the field of medical research, and a large number of kinetic and metabolic studies have been performed on human and animal physiology by means of radiotracers.
The extensive development of this field is due on one hand to a more thorough knowledge of physics and radiation applications, and on the other to the constant advances in radiation production, detection and utilization equipment. The most sophisticated equipment is expensive and requires highly specialized, multidisplinary personnel to operate it. This includes not only doctors, but also physicists, radiopharmacists and chemists who work in close collaboration. As a result, these services are often provided in only the largest medical centres that serve large centres of population. The input from the physicist emphasized the importance of radiation protection issues and the estimation of the absorbed dose in diagnostic procedures using radionuclides as well as the assessment of image quality and quantitative accuracy of radionuclide imaging.
SPECT and PET rely on the tracer principle, in which a minute quantity of a radiopharmaceutical in introduced into the body to monitor the patientÝs physiological function. In a clinical environment, resulting radionuclide images are interpreted visually to assess the physiological function of tissues, organs, and organ systems, or can be evaluated quantitatively to measure biochemical and physiological processes of importance in both research and clinical applications. This keynote lecture offers an overview of nuclear medical imaging physics and instrumentation with special emphasis on recent progress in image processing issues and integration of multimodality imaging in patient diagnosis and therapy planning. It begins with an introduction to various medical imaging modalities, and fundamental concepts in image reconstruction and quantification. Concluding remarks will include future directions in developments of hybrid imaging and applications in the optimisation of treatment volumes in external radiation therapy and patient-specific 3D dosimetry and treatment planning in targeted therapy.