Patient safety is also critical. Ideally, the radiopharmaceutical should exhibit no toxicity to the patient. While most commonly used compounds are inherently safe and provide wide margins of safety, we routinely inject drugs that are potentially toxic.
Thallous ion (Tl1+), for example, is known to be a potent cardiotoxin and yet we routinely inject Tl-201 thallous chloride intravenously into our patients. Why are we not concerned?
This is acceptable practice since the specific activity (activity per unit mass) of carrier-free Tl-201 is very high and the amount of Tl-201 contained in the typical 3 mCi dose (only 42 ng) is very small and significantly below the level required for a physiological response from the patient..
|Stephen Karesh, PhD.||
Last Updated: August 14, 1996