Quality of radiochemical purity in multiple samples of various fractionated cold kits: Testing a cost & time...

This study was aimed to assess technical aspects of fractionation of commonly used cold kits in Nuclear Medicine.

A total of 90 samples (30 samples each) of technetium-99m methylene diphosphonate (^99mTc-MDP), ^99mTc-diethylenetriaminepentaacetic acid (DTPA) and ^99mTc-dimercaptosuccinic acid (DMSA III) were taken on various days. The radiochemical purity was calculated of each fraction of these cold kits by using paper chromatography.

The mean value of radiochemical purity of ^99mTc -MDP, ^99mTc -DTPA and ^99mTc-DMSA(III) were calculated as ~ 95.12%, 91.43% and 95.68% and standard deviation (SD) were ~ 5.43, 8.36 and 3.88, respectively. Maximum time in which fractionation procedure completed i.e. time required for preparing the fraction or thawing was 10 minutes. All fractionated aliquots were between 1 and 15 days. Radiopharmaceutical bio-distribution was found to be appropriate during imaging in all samples.

Fractionation of cold kits using standardised technique is a time and cost-effective method and does not deteriorate the quality of labelling in commonly used pharmaceuticals in our study. We have used fractionated aliquots up to 3 days of preparation in patients with clinically usable radiochemical purity. Deep frozen fractions can be used up to 15 days in our experience.