Acute Tc-99m DMSA Scan for Identifying Dilating Vesicoureteral Reflux in Children: A Meta-analysis

Abstract

Controversy exists regarding the type and/or sequence of imaging studies needed during the first febrile urinary tract infection (UTI) in young children. Several investigators have claimed that because acute-phase Tc-99m dimercaptosuccinic acid (DMSA) renal-scan results are abnormal in the presence of dilating vesicoureteral reflux, a normal DMSA-scan result makes voiding cystourethrography (VCUG) unnecessary in the primary examination of infants with UTI. To evaluate the accuracy of acute-phase DMSA scanning in identifying dilating (grades III through V) vesicoureteral reflux documented by VCUG in children with a first febrile UTI, we performed a meta-analysis of the accuracy of diagnostic tests as reported from relevant studies identified through the PubMed and Scopus databases. Patient-based and renal unit-based analyses were performed. Overall, 13 cohort studies were identified. Nine studies involved patients younger than 2 years, 3 involved children aged 16 years or younger, and 1 involved exclusively neonates. Girls constituted 22% to 85% of the involved children. Pooled (95% confidence intervals) sensitivity and specificity rates of DMSA scanning were 79% and 53%, respectively, for the patient-based analysis (8 studies) and 60% and 65% for the renal unit-based analysis (5 studies). The respective areas under the hierarchical summary receiver operating curves were 0.71 and 0.67. Marked statistical heterogeneity was observed in both analyses, as indicated by I(2) test values of 91% and 87%, respectively. Acute-phase DMSA renal scanning cannot be recommended as replacement for VCUG in the evaluation of young children with a first febrile UTI.

Screening high-grade vesicoureteral reflux in young infants with a febrile urinary tract infection

“…The meta-analysis study shows the pooled sensitivity and specificity of DMSA scan were only 79% and 53%, respectively, for the patient-based analysis [26]. Data are quite similar to those in our study, with sensitivity 82.1% and specificity 56.1%.…”

“…The limitations of our study are that the quality of performance of prenatal US is not assured, and the information of voiding dysfunction is not evaluated. The use of DMSA scan is criticized for higher costs, longer duration, radiation exposure, and requirement of special equipment [26]. As pointed out by Flynn, it is difficult, even in developed countries, to schedule a every young child with febrile UTI for both US and DMSA scan during the acute episode [32].…”

Accuracy of Early DMSA Scan for VUR in Young Children With Febrile UTI

“…30 There are several reasons for this discrepancy. Compared with patients from the studies included in the metaanalysis, our study sample is highly heterogeneous and it may have included children with recurrent UTIs as well.…”

Delayed diagnosis of primary vesicoureteral reflux in children with recurrent urinary tract infections: Diagnostic approach and renal outcomes

“…[15][16][17] However, conclusions from two meta-analyses have demonstrated that acute-phase DMSA scintigraphy for predicting VUR was not accurate enough in children with fUTI. [18,19] In addition, it should be emphasized that there is no certain distinction between radiologically revealed congenital renal dysplasia and parenchymal inflammatory changes associated with acute pyelonephritis in young children. Therefore, the defects resulting from congenital dysplasia may be mistakenly identified as acute pyelonephritis on initial DMSA imaging.…”