Elucidation of Acute Renal Failure Due to Recurrent Non-Hodgkin Lymphoma by F-18 FDG PET/CT

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

OBJECTIVES

This study aims to evaluate whether (18)F-FDG excretion patterns reflect renal function in malignant obstructive uropathy and to evaluate if these patterns predict internal ureteral stent success.

METHODS

One hundred twelve patients who underwent PET/CT for abdominal tumors and displayed hydronephrosis on CT and 59 patients who underwent PET/CT for cancer screening were included in a retrospective study. Hydronephrosis was graded by initial CT and correlated with visual analysis of (18)F-FDG renal parenchymal uptake and excretion patterns. Stent insertion was performed for 84 patients after PET. Follow-up CT was reviewed for hydronephrosis improvement.

RESULTS

There were 4 PET patterns in obstructive hydronephrosis which correlated linearly with hydronephrosis severity and serum creatinine levels. Patients with no parenchymal retention and renal excretion (PET pattern 1) showed 97% (28/29) hydronephrosis improvement after stent insertion, and patients with no parenchymal retention and no renal excretion showed 0% (0/9) hydronephrosis improvement after stent insertion. Multivariate analysis showed creatinine levels and PET pattern predicted stent success, but CT hydronephrosis did not.

CONCLUSIONS

There are 4 PET patterns of obstructive hydronephrosis which correlated with hydronephrosis grade and creatinine levels. Some of these PET patterns can be useful in the prediction of hydronephrosis improvement after stent insertion. Recognition of these patterns in obstructive hydronephrosis may be helpful in improving patient prognosis and quality of life.

Diffuse FDG renal uptake in lymphoma

In patients presenting with acute renal failure and known/suspected lymphoma, the diagnosis of diffuse renal involvement is important, as there is potential for rapid resolution with chemotherapy. Although FDG is excreted through the kidneys and focal renal disease may be difficult to identify, diffuse renal FDG is more easily recognized and is always abnormal. We report a patient presenting with acute renal failure and suspected lymphoma. F-18 FDG PET/CT study demonstrated diffuse increased FDG uptake in bilaterally enlarged kidneys. Following 1 cycle of chemotherapy, the renal function normalized. An interim F-18 FDG PET/CT demonstrated normal size and FDG uptake within both kidneys.