What is a radiolabeled drug?

A radiolabeled drug is specifically defined as a drug that has been tagged with a radioactive isotope for tracking and diagnostic purposes. This tagging allows researchers and healthcare providers to trace the distribution and metabolism of the drug within the body using various imaging techniques, such as positron emission tomography (PET) or single-photon emission computed tomography (SPECT). The radioactive isotopes emit radiation that can be detected and used to visualize the drug's behavior, efficacy, and metabolism in real time, making it a crucial tool in both clinical and research settings, particularly in the fields of oncology, cardiology, and neuroscience.

The other options do not accurately capture the definition of a radiolabeled drug. While imaging techniques are involved in the application of radiolabeled drugs, not all medications administered through imaging techniques are radiolabeled. Moreover, a drug being approved by the FDA for radioactive treatment does not necessarily mean it is radiolabeled; it may not involve radioactivity at all. Lastly, labeling a compound for prescription only does not imply the presence of a radioactive isotope, making that option irrelevant to the definition of radiolabeled drugs. Thus, the accurate characterization of a radiolabeled drug is indeed the tagging of a drug with a radioactive isotope, which