18F-FDG (Fluorodeoxyglucose) is a glucose analogue which accumulates in tissue in proportion to the amount of glucose utilization. Increased consumption of glucose is characteristic of most cancers and is mostly related to overexpression of the GLUT glucose transporters and increased hexokinase activity. Once inside the cell, FDG is phosphorylated by the enzyme hexokinase and trapped.
18F-FDG PET/CT has become one of the cornerstones of patient management in oncology.
Indications for 18F-FDG PET/CT include, but are not limited to, the following:
- Differentiation between benign and malignant lesions;
- Screening for an unknown primary tumor when metastatic disease is discovered as the first manifestation of cancer or when the patien presents with a para-neoplastic syndrome;
- Initial staging patients with known malignancies;
- Distinguishing residual active tumor from post-treatment fibrosis or necrosis;
- Detecting tumor recurrence (restaging), especially in the ;presence of elevated tumor markers;
- Selection of a metabolically active region within a tumor most likely to yield diagnostic information for biopsy;
- Guiding radiation therapy planning.