Primary standardization of Radionuclide <sup>123</sup>I<i></i>

Short half-life radionuclides are essential for Nuclear Medicine. These radionuclides are usually linked to a more complex molecular or cellular structure with pharmacological characteristics. This set is called “radiopharmaceutical” and have been applied for the diagnosis and therapy of 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 and maintain the benefits of its use, the radiopharmaceutical dose must be administered to patients with high accuracy and precision, this places on National Metrology Institutes new requirements for improvement for primary standardization of these short half-life radionuclides, so that the standards used to calibrate the activity meters in hospitals and nuclear medicine clinics have the greatest possible precision. Iodine-123 is currently used for several applications in radiodiagnosis, the main being in pathologies and tumors in the thyroid. In this work is presented the primary standardization of 123I performed by 4παβ(LS)-γ(NaI(Tl)) live timed anticoincidence counting and no significant radionuclidic impurities have been detected by high resolution gamma ray spectrometry. With this work, LMNRI/IRD prepared for the key comparison of the BIPM K4 series using the SIRTI instrument.