Comparison between two absolute methods used for 177Lu activity measurements and its standardization

► Primary standardization of a 177Lu solution carried out under the auspices of the BIPM. ► Applications of the two absolute techniques, CIEMAT/NIST and 4?? integral counting. ► Identification and quantification of the long-lived 177mLu impurity in the mother solution. ► Calibration of the two ENEA re-entrant ionization chambers (ICs), one fixed and the other one portable, with uncertainty lower than 2%, typically used for routinely applications in the activity measurements of short-lived radionuclides useful for nuclear medicine.