Increased levels of Al3+ in Tc-99m eluate may cause concentration of the tracer in which organ?

Increased levels of aluminum ions (Al3+) in technetium-99m (Tc-99m) eluate can lead to tracer accumulation in the lungs due to the chemical behavior of aluminum when combined with certain radiopharmaceuticals.

Aluminum can act as a contaminant in the preparation of radiopharmaceuticals, and it is known to influence the clearance and distribution of the radiotracer in the body. When injected, Al3+ can interfere with the normal biodistribution of products like Tc-99m, particularly affecting the lung uptake. This is primarily due to the fact that the lungs can retain the aluminum, leading to a concentration effect in that area.

In scenarios where aluminum is present in technetium preparations, its tendency to deposit in various tissues may also be influenced by factors such as altered particle size or chelation properties. While other organs, like the liver, may become involved due to the metabolism and excretion of radiopharmaceuticals, the lungs are particularly noted for their increased retention of contaminants like aluminum when present in the Tc-99m eluate. Thus, the lungs are the organ that would most likely show increased tracer concentration under these conditions.