13 Preliminary experience with tc-99m-dmsa spect/ct in the diagnostic work up of complex renal calculi in children

• Published in: Archives of disease in childhood Vol. 102; no. Suppl 3; p. A17
• Main Authors: Hickson, M, Troncoso, B, Iacona, R, Ashford, F, Thurlow, B, Easty, M, Smeulders, N, Biassoni, L
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group LTD 01.10.2017
• Subjects: Calcification (ectopic); Children; Computed tomography; Kidney stones; Kidneys; Lithiasis; Medical diagnosis; Parenchyma; Pediatrics; Renal function; Single photon emission computed tomography; Tomography; Ultrasound; Urinary tract
• ISSN: 0003-9888; 1468-2044
• DOI: 10.1136/archdischild-2017-084620.43

BackgroundPaediatric urolithiasis is uncommon and severe complications, such as urinary tract infections and renal parenchymal scarring, occur in a minority of children with urinary calculi. The goals of management are to prevent additional renal damage, to expedite the passage of stones, and prevent new stone formation. The standard work-up for paediatric calculi includes ultrasonography followed by an abdominal x-ray. However complex calculi (for example staghorn calculi with extensive ramification in the renal collecting system) present a special diagnostic and therapeutic challenge.MethodsAt Great Ormond Street Hospital for Children a new imaging approach has been proposed in children presenting with complex renal calculi. This involves a Tc-99m-DMSA scan with planar and tomographic images for assessment of renal parenchymal function, followed by a low dose unenhanced CT KUB. The DMSA tomographic images are co-registered to the CT images.ResultsThis technique enables assessment of the function of the renal parenchyma adjacent to the renal stones. It has thus been possible to manage the calculi taking parenchymal function into account. For example, in the case of a horseshoe kidney in which one of the two moieties contained numerous stones, the DMSA scan showed very poor parenchymal function of that moiety: it was therefore decided to surgically resect the moiety instead of extracting the stones individually with percutaneous nephro-lithotomy (PCNL). Conversely, in a duplex kidney with stones in the lower moiety, the DMSA scan showed good parenchymal function of the lower moiety; as a result, this was not resected and the stones were extracted with PCNL. The radiation dose from this approach was no higher than the standard imaging protocol.ConclusionPreliminary results of this imaging approach in a selected patients’ population of more than 30 children with complex paediatric renal stones are encouraging and warrant further evaluation.