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.
Potassium iodide is a iodine-containing liquid that is used to protect the thyroid gland and to loosen secretions in the lungs (expectorant) so that they can be more easily coughed up (expectorated). Procedures that involve the use of radioactive iodine can damage the thyroid gland because the gland accumulates iodine.