If an assay shows 45 uCi of Mo99 in a Tc99m eluate, what should be done with the eluate?

The presence of 45 microcuries (uCi) of molybdenum-99 (Mo-99) in technetium-99m (Tc-99m) eluate indicates a significant contamination level of Mo-99, which is a parent radionuclide that decays to produce Tc-99m. According to safety and regulatory guidelines, the acceptable limit for Mo-99 contamination in Tc-99m is typically much lower than what is indicated in this assay result.

The decay of Mo-99 is not a viable solution in this case, since the half-life of Mo-99 is approximately 66 hours; thus, simply waiting for it to decay would not sufficiently mitigate the contamination risk before the eluate is used. Options involving using the eluate for other studies or only for the next 12 hours would still expose patients or staff to an unsafe level of Mo-99.

Therefore, the best course of action is to discard the eluate to prevent any potential radiation exposure to patients or staff due to the excessive Mo-99 contamination, ensuring compliance with safety standards. Discarding the eluate protects patient safety by eliminating the risk of using a radiopharmaceutical that does not meet acceptable purity criteria.