68Ga activity calibrations for nuclear medicine applications in Cuba

• Published in: Applied radiation and isotopes 2018-04, Vol.134, p.112-116
• Main Authors: Verdecia, P. Oropesa, Rodríguez, L. García, Águila, R.A. Serra, León, Y. Moreno, Magaña, Y. Jénez, Cassette, P.
• Format: Article
• Language: English
• Subjects: 22Na; 68Ga; Activity measurement; Calibration; Nuclear medicine; PET; Radionuclide calibrator; TDCR method
• ISSN: 0969-8043; 1872-9800
• DOI: 10.1016/j.apradiso.2017.11.010

The realization and dissemination of the 68Ga 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 68Ga solution using a Hidex™ commercial liquid scintillation counter and a FORTRAN code developed for the calculation of the 68Ga counting efficiencies in the given measurement system. The relative expanded uncertainty (k = 2) associated with the 68Ga 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 22Na - a positron emitter with a similar decay mode to the 68Ga disintegration scheme from the point of view of type of emitted particles detected in the measurement system. The observed difference between the measured 22Na activity concentration by the TDCR method and the corresponding reference value traceable to NIST is equal to 0.16%. Outcomes of transferring the 68Ga activity standard, realized with the TDCR method, to the secondary standard radionuclide calibrator Capintec CRC™ 15R and to three radionuclide calibrators used for 68Ga PET applications in a hospital are also shown. •The TDCR method is described for 68Ga using a Hidex™ commercial LS counter.•68Ga standard by TDCR transferred to Capintec CRC™ 15R radionuclide calibrator.•68Ga standard transferred to 3 hospital radionuclide calibrators used for 68Ga PET.