Interchangeability between 24-hour collection and single spot urines for vanillylmandelic and homovanillic acid levels in the diagnosis of neuroblastoma.

The determination of the two urinary catecholamine metabolites homovanillic acid (HVA) and vanillylmandelic acid (VMA) is of crucial importance for the diagnosis and follow-up of neuroblastoma (NB). The standard practice for their measurement requires the use of 24-hour collections that are time consuming and difficult to obtain. In this article, we directly demonstrate that 24-hour collections and single spot urines are interchangeable for the determination of HVA and VMA expressed as ratio on creatinine concentration. This study can be useful for a faster management of NB at onset.