Will the Radiation from the Isotope be  Harmful?

The amount of the radioisotope given to the patient is very less to cause any side effect or harm. The radiation dose received is medically insignificant. The target organs of the isotope in

the examination may receive the majority of the radiation dose, however, the amounts used are strictly controlled and regulated to use the least amount necessary for the purpose of imaging.

The patient may experience a  minimal discomfort. What

adds to the advantage of the test process is that the radioisotope is excreted from the body in some time and there is no trace that the test was ever done.

The excretion of the isotope is done by lungs, kidneys or the liver. Moreover, the radioactive substance decays by a natural phenomenon called physical decay. Say for example if 1unit of the substance was administered during a particular time, it would have reduced to half the quantity in some time and so on. In this way, all the substance that is given would be excreted out of the human body.