Question 22 • Physics in the Universe
Radioisotope imaging uses a radioactive tracer introduced into the body so its distribution can be detected. Radiopharmaceuticals are radioactive drugs that may be used for diagnosis or treatment, and brachytherapy treats disease by placing a radioactive source inside or near the target tissue. External beam radiation therapy delivers radiation from outside the body, so it does not involve placing radioactive material in the body.
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