Evaluation of 18F-FDG excretion patterns in malignant obstructive uropathy

Area of Science:

• Nuclear Medicine
• Radiology
• Urology

Background:

• Malignant obstructive uropathy can impair renal function.
• Assessing renal function and predicting treatment success in these patients is clinically important.
• Fluorodeoxyglucose (FDG) Positron Emission Tomography/Computed Tomography (PET/CT) offers insights into metabolic activity and excretion.

Purpose of the Study:

• To evaluate if (18)F-FDG excretion patterns reflect renal function in malignant obstructive uropathy.
• To determine if these patterns predict the success of internal ureteral stent placement.

Main Methods:

• Retrospective analysis of 112 patients with malignant obstructive uropathy and 59 controls undergoing PET/CT.
• Correlation of CT-based hydronephrosis grading with visual analysis of (18)F-FDG renal uptake and excretion patterns.
• Assessment of hydronephrosis improvement after ureteral stent insertion in 84 patients.

Main Results:

• Four distinct (18)F-FDG PET patterns were identified in obstructive hydronephrosis.
• (18)F-FDG patterns correlated linearly with hydronephrosis severity and serum creatinine levels.
• Patients with specific PET patterns (e.g., no parenchymal retention and renal excretion) showed significantly higher hydronephrosis improvement post-stenting (97%) compared to others (0%).
• Multivariate analysis indicated PET pattern and creatinine levels, but not CT hydronephrosis grade, predicted stent success.

Conclusions:

• Four PET patterns characterize obstructive hydronephrosis, correlating with disease severity and renal function (creatinine levels).
• Certain (18)F-FDG PET patterns are valuable predictors of hydronephrosis improvement following ureteral stent insertion.
• Utilizing these PET patterns can potentially enhance patient management and prognosis in obstructive uropathy.