Primary standardization of radionuclide 123I

Abstract

Short half-life radionuclides are essential for Nuclear Medicine. These radionuclides are mostly incorporated into more complex molecular or cellular structures possessing specific pharmacological characteristics. The resulting compound is called a radiopharmaceutical and is used for the diagnosis and therapy of various diseases. The use of radiopharmaceuticals involves exposure to ionizing radiation, which, although carefully controlled, poses potential health risks to patients and healthcare professionals. To minimize these risks while maintaining the benefits of radiopharmaceutical use, administered doses must be highly accurate and precise. This requirement imposes new demands on National Metrology Institutes (NMIs) to improve primary standardization methods for short half-life radionuclides, ensuring that the standards used to calibrate activity meters in hospitals and nuclear medicine clinics achieve the highest possible precision. Iodine-123 (^123I) is currently used in several radiodiagnostic applications, primarily for evaluating thyroid pathologies and tumors. This work presents the primary standardization of ^123I performed using the 4πβ(LS)-γ(NaI(Tl)) live-timed anticoincidence counting method. High-resolution gamma-ray spectrometry detected no significant radionuclidic impurities. Through this work, LMNRI/IRD was prepared for the BIPM K4 series key comparison using the SIRTI instrument.