What type of radiotracer is commonly used in PET scans?

• A. Fluorodeoxyglucose (FDG)
• B. Technetium-99m
• C. Iodine-123
• D. Carbon-11

Answer: (A)

Fluorodeoxyglucose (FDG) is commonly used in PET scans primarily because it effectively measures metabolic activity in tissues, particularly in identifying cancer lesions. FDG is a glucose analog that is taken up by cells in a manner similar to glucose. When there is increased metabolic activity, such as in cancerous tumors, the uptake of FDG is higher, making it possible for clinicians to visualize and assess tumor behavior through PET imaging.

This characteristic is fundamental in oncology as it helps in both cancer diagnosis and treatment monitoring. The other radiotracers, while useful in specific contexts, do not have the same level of application in standard PET scans due to their different biological behavior and imaging capabilities. For example, Technetium-99m is primarily used in single-photon emission computed tomography (SPECT) imaging, while Iodine-123 is often utilized in thyroid imaging. Carbon-11, although used in research settings and certain specialized applications, is not as widely employed as FDG in clinical PET practice.