Which of the following radiopharmaceuticals is not prepared with reduced 99mTc pertechnetate?

The preparation of various radiopharmaceuticals for use in nuclear medicine often relies on the main radioactive isotope technetium-99m (99mTc), usually in its reduced pertechnetate form. This form allows for efficient labeling of pharmaceuticals that can target specific organs or tissues in the body.

In the case of 99mTc sulfur colloid, it is prepared using colloidal particles rather than utilizing reduced 99mTc pertechnetate. Instead, sulfur colloids are made by mixing 99mTc in its reduced form with various materials, which then undergo a process that involves condensation and aggregation. This results in a stable suspension of particles that can be used for imaging the reticuloendothelial system (RES).

The other options—involving medronate, oxidronate, and macroaggregated albumin—specifically require reduced technetium for effective binding and are characterized by their ability to target specific tissues effectively, which reflects the advantage of using reduced 99mTc pertechnetate in their preparation. These radiopharmaceuticals are made to ensure that the technetium binds strongly to the specific agent that is used to track physiological processes.

Therefore, the choice involving 99mTc sulfur collo