Dimercaptosuccinic acid scan challenges in childhood urinary tract infection, vesicoureteral reflux and renal scarring investigation and management.

Abstract

Vesicoureteral reflux (VUR) is a precipitating factor in acute pyelonephritis (APN), and a risk factor for renal scar formation, even if VUR and APN occur independently. There is no scientific evidence on a specific diagnostic evaluation of children after a febrile urinary tract infection (UTI). Based on recent literature and our clinical experience, we reviewed the role of 99mTc dimercaptosuccinic acid (DMSA) renal scan in UTI/VUR imaging. We also reviewed the DMSA challenges and controversies in UTI/VUR management. A DMSA renal scan is the most reliable tool for the establishment of the diagnosis of APN during febrile UTIs acute phase. The "top-down" approach focuses on kidney involvement during UTI rather than on VUR existence, with a goal of diagnosing APN and/or renal dysplasia. Therefore, DMSA is performed before void cysteourethrography (VCUG). Late DMSA scanning should be performed to evaluate the presence of permanent renal scars. DMSA may be considered valuable in the follow-up of children with VUR, in order to detect new renal scarring after breakthrough or recurrent UTIs. An abnormal DMSA scan comprises a risk factor for VUR identification after UTI, for recurrent UTIs, renal damage/scarring, renal function deterioration, and a negative predictive risk factor for VUR improvement and/or spontaneous resolution. An individualized DMSA risk-based dynamic approach may assist physicians on VUR management decisions. DMSA could play an important role in selecting children with UTI/VUR who would benefit from close monitoring and/or early intervention. However, more data are needed for evidence-based guidelines.