What is the most commonly used radiopharmaceutical for PET imaging?

Fluorine-18 is the most commonly used radiopharmaceutical for positron emission tomography (PET) imaging due to its favorable properties. It is primarily used in the form of fluorodeoxyglucose (FDG), which is a glucose analog. Since many cancer cells have higher rates of glucose metabolism compared to normal tissues, FDG uptake is significantly higher in malignant tumors, making it an excellent tracer for cancer diagnosis, staging, and monitoring treatment response.

Additionally, Fluorine-18 has a half-life of approximately 110 minutes, allowing ample time for patient imaging while still providing sufficient radioactivity for detection by the PET scanner. Its relatively low radiation dose and effectiveness in targeting metabolic activity are characteristics that contribute to its widespread use in clinical settings.

While Carbon-11 and Gallium-68 are also used in specific applications within PET imaging, they are not as widely employed as Fluorine-18 due to factors like shorter half-lives or less availability in routine clinical practice. Technetium-99m, although a highly utilized isotope in other imaging modalities like SPECT, is not used for PET imaging at all. Thus, Fluorine-18 remains the primary choice for PET radiopharmaceuticals in clinical use.