How the 99mTc-DMSA scintigraphy findings are reflected in the adopted treatment of primary vesicoureteral reflux: One centre experience

Abstract

Background: Renal changes may have long-term sequalae and prevention is a main goal of management of primary vesicoureteral reflux (VUR).

Aim: This study aims to reveal how much ^99mTc-DMSA scintigraphy findings are reflected in the adopted surgical or non-surgical treatment in children with diagnosed primary VUR and to give the clinicians information regarding their final therapeutic decision.

Patients and methods: A total 207 children with primary VUR who underwent non-acute ^99mTc-DMSA scan were retrospectively evaluated. The presence of renal changes, their grading, differential function asymmetry (<45%) and grade of VUR were compared with subsequent choice of therapy.

Results: Altogether 92 (44%) children had asymmetric differential function, 122 (59%) showed presence of renal changes, 79 (38%) had high-grade VUR (IV-V). Patients with renal changes had lower differential function (41%vs.48%) and higher grade of VUR. The incidence of high-grade changes (G3+G4B) afflicting more than one third of the kidney was significantly different between grade I-II, III and IV-V VUR (9%, 27%, 48%, respectively). Renal changes were detected in 76% of surgically and 48% of non-surgically treated patients, high-grade ^99mTc-DMSA changes in 69% and 31%, respectively. In children with no scars/dysplasia (G0+G4A), non-surgical treatment prevailed in 77%. The independent predictors for surgical intervention were presence of renal changes and higher grade of VUR, but not functional asymmetry.

Discussion: Over the last 20 years, there has been a shift toward more non-surgical management of VUR. The long-term outcome of this approach should be thoroughly studied. This is the first study analysing renal status in VUR patients using ^99mTc-DMSA scan and its grading regarding the adopted treatment. Renal changes in almost half of non-surgically treated children with VUR should be an indicator for earlier diagnosis and effective treatment of acute pyelonephritis and VUR. We recommend distinguishing grade III VUR, as a moderate-grade VUR, because it is linked to higher incidence of high-grade ^99mTc-DMSA changes (G3+G4B); our findings of 65% of grade III VURs treated non-surgically should be cautionary. Grade III VUR does not mean a low-risk condition and should alert the clinician to evaluate the extent of renal changes and unmask high-risk cases.

Conclusions: Our data strengthens the need to investigate the extent of renal changes in VUR patients regarding treatment decision. Performing ^99mTc-DMSA scan individualizes the treatment of VUR patients; its grading can distinguish grade III-VUR as a separate risk entity because it differs significantly in terms of incidence of high-grade renal changes and chosen therapy.

Keywords: (99m)Tc-DMSA scintigraphy; (99m)Tc-DMSA scintigraphy grading; Asymmetric renal function; Renal parenchymatous changes; Renal scars; Vesicoureteral reflux.