The invention relates to nuclear medical devices, in particular, to the manufacture of
radionuclide generators. A
strontium-82 /
rubidium-82 generator includes a generator column with a
sorbent based on hydrated
tin (IV)
oxide, to which the radioactive
isotope 82Sr (half-life of 25.55 days) with the
impurity 85Sr (half-life of 60 days) is applied. 82Sr decays to short-lived 82Rb (half-life of 76 seconds). The generator is intended for producing a radiopharmaceutical containing 82Rb
chloride, which is washed off the
sorbent and administered to a patient for diagnosing various diseases using
positron emission
tomography, while the
strontium-82 and 85 isotopes should remain on the
sorbent and should not pass into the eluate together with 82Rb. In this generator, the maximum volume of the obtained 82Rb-containing eluate with a content of 82Sr and 85Sr below the permissible level (0.01 and 0.1 kBq per 1 MBq of 82Rb, respectively) depends on the concentration of ions of stable isotopes of
calcium (CCa) and
strontium (CSr) on the sorbent arising during the preparation and use of the generator, and is limited by the value of 0.11 CCa + CSr. For example, the production of more than 17 liters of eluate with an acceptable content of 82Sr and 85Sr is achieved when this ratio is below 0.67 µmol per 1 g of dry sorbent. The production of more than 30 liters of eluate is achieved when this value is lower than 0.33 µmol per 1 g of dry sorbent (when the weight of specially prepared dry sorbent in the column is not less than 3.8 g). The limits of the amount of
calcium and strontium arising on the sorbent during manufacture of the generator are proportional to the weight of the sorbent in the column. Thus, at a relatively low concentration of
calcium and
strontium ions and with a sorbent weight in the column of more than 3.8 g, a larger volume (31-60 liters) of a radiopharmaceutical in the form of a solution of 82Rb
chloride with the necessary characteristics can be obtained using the generator. A larger volume of radiopharmaceutical allows increasing the number of patients examined with each generator. Also, observing the given limit for the strontium and calcium
ion content in the sorbent allows preventing more reliably radioactive strontium isotopes from entering the patient.