RADIONUCLIDE TARGETING AND DOSIMETRY AT THE MICROSCOPIC LEVEL - THE ROLE OF MICROAUTORADIOGRAPHY

The understanding of localisation mechanisms and microdosimetry of dia gnostic and therapeutic radiopharmaceuticals depends on knowledge of t heir biodistribution at the microscopic level (cellular and subcellula r) in the target tissues. Various methods have been advanced for obtai ning information about this microdistribution: subcellular fractionati on, secondary ion mass spectrometry imaging, microprobe elemental anal ysis in the electron microscope, and microautoradiography. This review compares these approaches, and discusses in detail the methodology of microautoradiography (the most generally useful approach) with imagin g and therapy radionuclides, Literature examples of applications of mi croautoradiography in nuclear medicine are reviewed, and the future po tential contribution of the techniques is assessed.