radiofarmaca

Radiopharmaceuticals are medicinal formulations that contain a radioactive substance and are designed for use in nuclear medicine. They serve diagnostic or therapeutic purposes by delivering radioactive energy to specific biological targets in the body.

Production and composition: A radiopharmaceutical combines a radionuclide with a pharmaceutical ligand or targeting vector, such as a small molecule, peptide, or antibody. The radionuclide may be produced in a cyclotron or a nuclear reactor, and the resulting compound is prepared under sterile conditions with attention to radiochemical purity and apyrogenicity. Radiopharmaceuticals have short half-lives, requiring on-site or nearby production and rapid administration.

Diagnostic radiopharmaceuticals are used for functional imaging. Common isotopes include technetium-99m, fluorine-18, and gallium-68. Imaging modalities include SPECT and PET. Examples include Tc-99m–labeled compounds for bone scans, F-18 FDG for metabolic imaging, and Ga-68–labeled somatostatin analogs for neuroendocrine tumor imaging.

Therapeutic radiopharmaceuticals deliver cytotoxic radiation to disease targets. Examples include iodine-131 for thyroid disease, lutetium-177 DOTATATE for neuroendocrine tumors, and radium-223 dichloride for skeletal metastases. Emerging approaches include alpha-emitting therapies and theranostic pairs that enable matching diagnostic and therapeutic radiopharmaceuticals for individual patients.

Safety and regulation: Radiopharmaceuticals are regulated under pharmaceutical GMP standards and radiological protection guidelines. Quality control includes radiochemical purity, sterility, pyrogenicity, and appropriate specific activity. Handling requires specialized facilities, trained personnel, and regulatory oversight by agencies such as the FDA or EMA, with emphasis on minimizing radiation exposure (ALARA).

See also: nuclear medicine, dosimetry, theranostics.