{68}$GA activity calibrations for nuclear medicine applications in Cuba

• Published in: Applied radiation and isotopes 2018-05, Vol.134 (SI), p.112-116
• Main Authors: Oropesa Verdecia, P., Garcia Rodriguez, L., Serra Aguila, R. A., Moreno Leon, Y., Jenez Magana, Y., Cassette, Philippe
• Format: Article
• Language: English
• Subjects: Computer Science; Modeling and Simulation; Nuclear Experiment; Physics
• ISSN: 0969-8043; 1872-9800
• DOI: 10.1016/j.apradiso.2017.11.010

The realization and dissemination of the $^{68}$Ga activity measurement unit in Cuba is presented. Firstly, the implementation of the Triple to Double Coincidence Ratio (TDCR) method is described for the calibration of the activity concentration of a $^{68}$Ga solution using a Hidex (TM) commercial liquid scintillation counter and a FORTRAN code developed for the calculation of the $^{68}$Ga counting efficiencies in the given measurement system. The relative expanded uncertainty ($k$ = 2) associated with the $^{68}$Ga activity concentration obtained with the TDCR method is equal to 2%. With the aim to validate this measurement uncertainty estimate, the method is also applied to an Amersham standard solution of $^{22}$Na - a positron emitter with a similar decay mode to the $^{68}$Ga disintegration scheme from the point of view of type of emitted particles detected in the measurement system. The observed difference between the measured $^{22}$Na activity concentration by the TDCR method and the corresponding reference value traceable to NIST is equal to 0.16%. Outcomes of transferring the $^{68}$Ga activity standard, realized with the TDCR method, to the secondary standard radionuclide calibrator Capintec CRC™ 15R and to three radionuclide calibrators used for $^{68}$Ga PET applications in a hospital are also shown.