Radiopharmaceuticals

Excerpt

A radiopharmaceutical consists of 2 components: a radionuclide, which is a radioactive agent, and a pharmaceutical molecule, which acts as a tissue-localizing agent. These compounds are used for diagnostic or therapeutic interventions. Although the administration of radiopharmaceuticals is often systemic, they are likely to localize to specific tissues due to their biomolecular properties, ie, the areas of hyperintensity observed on positron emission tomography (PET) scans that indicate high tissue metabolic demand. In PET scans, positrons emitted by the radionuclide collide with electrons in the tissue, producing gamma rays that are detected by the scanner to create detailed images of metabolic activity. Because badiopharmaceuticals (the radionuclide component) actively emit radiation, their storage is more complex than that of non-radioactive pharmaceuticals. Proper handling and disposal of radiopharmaceuticals are crucial to ensure safety and prevent environmental contamination, including wearing appropriate protective clothing, using shielding devices during preparation and administration, and following strict protocols for waste disposal. Compounds used for diagnostic interventions typically emit positrons (beta-plus particles) for PET imaging or gamma rays for single-photon emission computed tomography. In contrast, agents that emit electrons (beta-minus particles), Auger electrons, or alpha particles (helium nuclei) are generally used for therapeutic interventions.