Optimization of urinary FDG excretion during PET imaging.

Area of Science:

• Nuclear Medicine
• Radiopharmacology
• Renal Physiology

Background:

• Urinary fluorodeoxyglucose (FDG) accumulation poses a significant challenge in Positron Emission Tomography (PET) imaging, often obscuring visualization of pelvic and abdominal structures.
• Limited data exists on physiological factors influencing FDG urinary excretion, hindering efforts to minimize this interference during PET scans.

Purpose of the Study:

• To investigate physiological variables affecting FDG urinary excretion.
• To evaluate the impact of hydration and diuretic treatment on FDG excretion in both animal models and human subjects undergoing PET imaging.

Main Methods:

• FDG urinary excretion was measured in rats under normal, hydrated, hydrochlorothiazide-treated, and phlorizin-treated conditions.
• FDG clearance rates were compared to glomerular filtration rates in rats.
• FDG excretion was assessed in hydrated and dehydrated human patients undergoing PET scans.

Main Results:

• Hydrated and phlorizin-treated rats exhibited the highest FDG excretion.
• Hydrochlorothiazide increased urine volume but not FDG excretion percentage.
• Hydrated patients showed significantly higher FDG excretion and urine volume compared to dehydrated patients.

Conclusions:

• Hydrochlorothiazide increases urine volume but does not enhance FDG excretion.
• Patient hydration before PET scanning increases FDG delivery to the bladder.
• Diuretics may be a preferable method for increasing urinary volume without augmenting FDG delivery to the bladder.