From the Guidelines
The most commonly used radioactive tracer in Positron Emission Tomography (PET) scans is 18F-FDG, a glucose analogue that accumulates in tissues with high metabolic activity, such as cancer cells. This tracer is a cyclotron-produced radioisotope of fluorine that emits positrons and has a short half-life of 109.7 minutes, allowing it to be imaged within a few hours after injection 1. The use of 18F-FDG in PET scans enables noninvasive quantitative assessment of biochemical and functional processes, including glucose utilization, which is characteristic of most cancers.
Some key points to consider when using 18F-FDG in PET scans include:
- The tracer is taken up by living cells via cell membrane glucose transporters and subsequently incorporated into the first step of the normal glycolytic pathway 1
- FDG accumulation in tissue is proportional to the amount of glucose utilization, making it a sensitive imaging modality for detection, staging, and restaging of cancer 1
- The combination of PET and CT (PET/CT) provides essential information for radiation treatment planning and helps with critical decisions when delineating tumor volumes 1
- The use of 18F-FDG in PET scans requires standardization and harmonization of diagnostic quality and quantitative information, particularly in multicenter settings 1
Overall, 18F-FDG is a highly effective and widely used radioactive tracer in PET scans, particularly in oncology, due to its ability to accumulate in tissues with high metabolic activity and provide quantitative information on glucose utilization.
From the FDA Drug Label
Fludeoxyglucose F 18 Injection, USP is a positron emitting radiopharmaceutical containing no-carrier added radioactive 2-deoxy-2-[18F]fluoro-D-g1ucose, which is used for diagnostic purposes in conjunction with Positron Emission Tomography (PET). The active ingredient 2-deoxy-2-[18F]fluoro-D-g1ucose (Fludeoxyglucose F 18), abbreviated [18F] FDG, has a molecular formula of C6H1118FO5 with a molecular weight of 181.26 Daltons... Fluorine F 18 decays by positron (β+) emission and has a half-life of 109. 7 minutes.
The radioactive tracer used by Positron Emission Tomography (PET) scan is [18F] FDG (Fludeoxyglucose F 18), which contains the radioactive isotope Fluorine F 18 2.
- Key characteristics:
- Molecular formula: C6H1118FO5
- Molecular weight: 181.26 Daltons
- Half-life: 109.7 minutes
- Decays by positron (β+) emission
From the Research
Radioactive Tracers Used in PET Scans
- A radioactive tracer commonly used by Positron Emission Tomography (PET) scans is 18F-FDG (fluorodeoxyglucose) 3, 4, 5, 6, which is a glucose analog that allows for the evaluation of glucose metabolism.
- 18F-FDG is the most commonly used tracer in oncology due to its practical half-life of 110 minutes 3.
- The uptake of 18F-FDG in tumors is proportional to the glycolytic metabolic rate of viable tumor cells, indicating the increased metabolic demand of tumors for glucose 3.
- Other tracers are also used in PET scans, such as oxygen-15 for blood flow measurements and 11C-based compounds for neuronal disorders 7.
- Radiolabeled tracers, such as [18F]-FDG and NA [18F], are used for various medical conditions, including cancer, brain pathologies, and bone lesions 7.