Nomenclature of ^99mTc-Technetium-Labeled Radiopharmaceuticals

TO THE EDITOR:

Dr. Tewson is quite right when he points out in his letter that technetium chemists are somewhat lax in the description of their agents (1). In his example, ^99mTc-ciprofloxacin is internally contradictory in that it implies that ciprofloxacin contains the atom technetium, which of course it does not.

The pharmacopoeias do use the correct names: for example, technetium ^99mTc medronate. Apart from sestamibi and one or two others, in general the chemical names of radiopharmaceuticals do not include technetium so “technetium ^99mTc” must be added in each instance, which really is unworkable for routine use. It’s too late to close the barn door.

He also makes the point that an exact chemical structure is required for reproducible results to be obtained. The aforementioned technetium ^99mTc medronate is a constantly changing mixture of several complexes, all of which are taken up by bone and have been used, apparently reproducibly, for 30 y in the most popular nuclear medicine procedure in the world.

However, I would like to make this proposal: I will lobby the SPECT community to tighten up its nomenclature if he can persuade his colleagues in the PET world to discard the incorrect term ¹⁸F-fluorodeoxyglucose (FDG) when they really mean ¹⁸F-2-deoxy-2-fluoro-d-glucose!