Is VCUG still indicated following the first episode of urinary tract infection in boys?

To determine if voiding cystourethrogram (VCUG) following first episode of urinary tract infection (UTI) offers any incremental diagnostic advantage in boys if a comprehensive renal and bladder ultrasonogram (RBUS) revealed no abnormalities.

All boys less than 10 years of age whose first evaluation for UTI included RBUS and VCUG were retrospectively studied over a 10-year period. Those with a disorder of the urinary tract known before imaging were excluded. RBUS and VCUG results were analyzed.

Of the 77 who met the inclusion criteria, 58 (77%) were <1 year old. 45 (58%) boys had normal RBUS and VCUG. In 16 (21%) both studies were abnormal: 15 had vesicoureteral reflux (VUR) and one had posterior urethral valves. The remaining 16 (21%) had one abnormal study: 10 had pelvicaliectasis on RBUS without VUR; 6 had normal RBUS with VUR. No urethral abnormality was diagnosed on VCUG when RBUS was normal. Of the six who had VUR and normal RBUS, the one who required surgical intervention had recurrent febrile UTI.

If a well-performed RBUS is normal in a boy with first UTI, the likelihood of a significant finding in VCUG is low. A VCUG is likewise of no apparent screening benefit for obstructive uropathy. With the uncertainties surrounding the benefit of chemoprophylaxis, omitting a VCUG when a RBUS is normal in boys with a first UTI avoids the morbidity without missing important pathologies or altering evolving management protocols.