Hyperglycemia and Hyperinsulinemia in FDG-PET Imaging

Acute hyperglycemia can cause decreased uptake of FDG by tumor cells, decreasing sensitivity. Hyperglycemia can also stimulates insulin release, which preferentially drives glucose and FDG into skeletal muscle. Glucose loading has been shown to have a greater effect on FDG uptake in inflammatory lesions than in tumors, which has been suggested as a way of differentiating the two. However, I haven't seen this used in practice.

Chronic hyperglycemia is a different, and more controversial issue.

On the other side of the spectrum, hyperinsulinemia can diffusely increase uptake of FDG and can lower sensitivity by decreasing the amount of FDG available to tumor cells. The Society of Nuclear Medicine recommends that if insulin is considered to normalize blood glucose, the administration of FDG be delayed for a time period depending on the type and route of administration of insulin.

References

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