DMSA study performed during febrile urinary tract infection: a predictor of patient outcome?
Technetium-99m dimercaptosuccinic acid (DMSA) study has been advocated as a method for the assessment of renal sequelae after acute febrile urinary tract infection (UTI). However, it is not known whether DMSA scintigraphy performed during acute UTI has any prognostic value for outcome assessment. The objective of this study was to evaluate the usefulness of DMSA scintigraphy performed during UTI as a predictor of patient outcome, to identify children at risk of events [vesico-ureteral reflux (VUR) or recurrent UTI] that may lead to the development of progressive renal damage. One hundred and fifty-two children (including 78 girls) with a mean age of 20 months (range 1 month to 12 years) with first febrile UTI were evaluated by DMSA scintigraphy during acute UTI. After acute UTI, children were explored by voiding cysto-urethrography. Children who presented an abnormal DMSA study, or a normal DMSA study but VUR or recurrent UTI, underwent a DMSA control study 6 months after UTI. Children with VUR were followed up by direct radionuclide cystography. DMSA scintigraphy performed during acute UTI was normal in 112 children (74%). In 95 of these children, follow-up DMSA scintigraphy was not performed owing to a good clinical outcome. In the remaining 17 children, follow-up scintigraphy was normal. Forty children (26%) presented abnormal DMSA study during acute UTI. Twenty-five of them presented a normal follow-up DMSA, and 15 presented cortical lesions. Children with abnormal DMSA had a higher frequency of VUR than children with normal DMSA (48% vs 12%). It is concluded that children with normal DMSA during acute UTI have a low risk of renal damage. Children with normal follow-up DMSA and low-grade VUR have more frequent spontaneous resolution of VUR.