Fractionated elution of 99Mo/99mTc generators using calibrated vials

Area of Science:

• Radiopharmacy
• Nuclear Medicine
• Elution Techniques

Background:

• Fractionated elution collects eluate fractions with high radioactive concentration.
• This technique is valuable for specific clinical radiopharmacy applications.
• Current methods for fractionated elution on Mo/Tc generators can be improved for ease of use and reproducibility.

Purpose of the Study:

• To describe and evaluate simple fractionated elution procedures for both dry column generators (DCG) and wet column generators (WCG) using calibrated vials.
• To determine the relationship between eluate volume and elution yield for both generator types.
• To assess the repeatability of the fractionated elution procedure.

Main Methods:

• Calibrated elution vials were used to achieve specific eluate volumes by air addition (WCG) or saline subtraction (DCG).
• Regression models established the relationship between eluate volume (V) and elution yield (Y) for DCG and WCG.
• Repeatability was assessed using 3-ml vial calibrations with multiple elutions (n≥30 for DCG, n≥31 for WCG).

Main Results:

• Regression equations for DCG and WCG were Y=57.551 ln(V)+10.526 and Y=50.256 ln(V)+17.597, respectively.
• Repeatability tests showed median volumes of 2.98 ml (DCG) and 3.28 ml (WCG), with median yields of 84.73% (DCG) and 81.78% (WCG).
• WCG produced significantly higher and more variable volumes, and lower elution yields compared to DCG.

Conclusions:

• Fractionated elution with calibrated vials is a straightforward and effective method for both DCG and WCG.
• The procedure demonstrates better reproducibility with DCG than WCG.
• This method provides a reliable way to perform fractionated elution, especially for DCG.