Estimating GFR in children with 99mTc-DTPA renography: a comparison with single-sample 51Cr-EDTA clearance.

Glomerular filtration rate (GFR) measurement by (51)Cr-ethylenediaminetetraacetic acid (EDTA) and blood sampling in children is usually cumbersome for the patient, parents and laboratory technicians. We have previously developed a method accurately estimating GFR in adults. The aim of the present study was to evaluate the accuracy of this non-invasive method in children. We calculated GFR from (99m)Tc-diethylene triamine pentaacetic acid (DTPA) renography and compared with (51)Cr-EDTA plasma clearance of 29 children between the age of 1 month and 12 years (mean 4.7 years). The correlation between (99m)Tc-DTPA renography and (51)Cr-EDTA plasma clearance was for all children R = 0.96 (n = 29, P<0.0001), for children above 2 years of age R = 0.96 (n = 18, P<0.0001) and for children <2 years R = 0.84 (n = 11, P<0.001). We conclude that assessment of GFR from (99m)Tc-DTPA renography is reliable and comparable to GFR calculated from (51)Cr-EDTA plasma clearance. Because our method is non-invasive and only takes 21 min, it may be preferable in many cases where an assessment of renal function is needed in children especially when renography is performed anyhow.