Which statement best describes the relationship between radiopharmaceuticals and their chemical properties?

• A. Radiopharmaceuticals are compounds whose chemical properties determine their distribution and function in the body.
• B. Radiopharmaceuticals have identical chemical properties to non-radioactive pharmaceuticals.
• C. Radiopharmaceuticals do not interact chemically with biological tissues.
• D. Radiopharmaceuticals are only defined by their radioactive decay, not by their chemical properties.

Answer: (A)

Verified step by step guidance

1. Step 1: Understand what radiopharmaceuticals are — they are compounds that contain a radioactive isotope used for diagnosis or treatment in medicine.
2. Step 2: Recognize that the chemical properties of a radiopharmaceutical influence how it behaves in the body, including how it is absorbed, distributed, metabolized, and excreted.
3. Step 3: Note that the radioactive part provides the signal for imaging or therapy, but the chemical structure determines where and how the compound interacts with biological tissues.
4. Step 4: Compare the options by considering whether radiopharmaceuticals have unique chemical properties or if their behavior is solely due to radioactivity; the correct understanding is that chemical properties are crucial for their function.
5. Step 5: Conclude that the best description is that radiopharmaceuticals are compounds whose chemical properties determine their distribution and function in the body.