definitions - understudies. understudy (n.) 1.someone who takes the place of another (as when things get dangerous or difficult)the star had a stand-in for dangerous scenes we need extra employees for summer fill-ins. 2.an actor able to replace a regular performer when required. understudy (v.)
Radiation can come in the form of a pill. Iodine (131 I) used in thyroid treatment might be given in pill form or as a liquid. The choice is an institutional decision based on many factors, including the amount to be given to a patient.
For a thyroid scan, you will either swallow a dose of radioactive iodine or be given technetium in a vein (intravenously) in your arm. When and how you take the radioactive tracer depends on which tracer is used. 1  Iodine can be taken as a capsule or a fluid 4 to 24 hours before the scan is done.