Patient safety is also critical. Ideally, the therapeutic 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. 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.
One of the concerns regarding treating a patient with I-131 NaI therapy solution is whether the patient is allergic to iodine. A calculation will show that 10 mCi of carrier-free I-131 contains only 80 ng of elemental iodine, far too small an amount to have a physiological effect on the patient.
|Stephen Karesh, PhD.||
Last Updated: August 14, 1996