Domain III(A): elute radionuclide generator, perform, & evaluate QC tests

99Mo/99mTc generator

- most commonly used generator type in nuclear medicine which allows for extraction of Tc-99m

99Mo/99mTc generator

- saline passes through alumina column

- Mo-99 stays tightly bound to the column & the pertechnetate ion is removed by the Cl- ion

2 weeks

99Mo/99mTc generator shelf-life

23 hours

amount of time needed for maximum extraction of Tc-99m from 99Mo/99mTc generator

1 month

82Sr/82Rb generator shelf-life

82Sr/82Rb generator

- saline passes through alumina column

- Sr-82 stays tightly bound to the column & Rb-82 is removed

transient equilibrium

equilibrium:

- parent half-life is longer than daughter half-life

daughter activity will rise & surpass the parent activity, then decrease to a rate parallel to that of the parent

secular equilibrium

equilibrium:

- parent half-life is very long to the point where the decay rate is negligible over the time period required for the daughter to decay

- parent activity remains constant while the daughter activity gradually accumulates

- met when daughter activity = parent activity

eluate

extracted from the generator

dose calibrator

used to determine the amount of activity eluted & the concentration

0.15uCi Mo-99 per mCi of Tc-99m

radionuclidic 99Mo breakthrough limit

Mo-99 breakthrough

looks for presence of Mo-99 contamination with an eluate

Al+3 breakthrough

confirms amount of aluminum ion present within a radiopharmaceutical

10 ug Al/mL of eluate

Al+3 breakthrough limit

dose calibrator

- used to measure dose activity before/after patient administration

- operates in ionization region

- operates in current mode

constancy

dose calibrator QC performed daily, at install, after repair

constancy

ability of meter to measure same activity reading each day of use

constancy

performed with a single long-lived standard (Cs-137)

linearity

dose calibrator QC performed quarterly, at install, after repair

linearity

correctness of activity reading across a wide range of dose activities

decay method

- measure source at multiple intervals until it decays down to 30 uCi

- graph measurements on semilogarithmic paper

sleeve method (calicheck)

- commercial lead sleeves that simulate decay through attenuation

- absorbs the Tc-99m photons & the Mo-99 photons pass through

accuracy

dose calibrator QC performed annually, at install, after repair

accuracy

- correctness of reading compared to true decay corrected value for a long-lived source

- measured with at least 2 sealed NIST reference standards

geometry

dose calibrator QC performed after change in configuration, at install, after repair

geometry

correctness of reading based on container size/shape/material/volume