Ga-68 activity calibrations for nuclear medicine applications in Cuba
Abstract
The realization and dissemination of the Ga-68 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 Ga-68 solution using a Hidex (TM) commercial liquid scintillation counter and a FORTRAN code developed for the calculation of the Ga-68 counting efficiencies in the given measurement system. The relative expanded uncertainty (k = 2) associated with the Ga-68 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 Na-22 - a positron emitter with a similar decay mode to the Ga-68 disintegration scheme from the point of view of type of emitted particles detected in the measurement system. The observed difference between the measured Na-22 activity concentration by the TDCR method and the corresponding reference value traceable to NIST is equal to 0.16%.