Comparison between Tc-99m DTPA and Tc-99m MAG3 Renal Scintigraphy for Prediction of Early Adverse Outcome After Kidney Transplantation.

Abstract

Renal scintigraphy (RS) with either technetium-99m diethylene-triamine-pentaacetate (Tc-99m DTPA) or technetium-99m mercaptoacetyltriglycine (Tc-99m MAG3) has both been used to evaluate early allograft function after kidney transplantation (KT). This study was done to compare the predictive performance of RS using these two radiopharmaceuticals for prediction of outcomes during first 3months of KT. This retrospective study included patients who received KT then underwent both Tc-99m DTPA and Tc-99m MAG3 RS, successively. Receiver operating characteristic (ROC) curve analysis was used to determine the predictiveness of RS parameters on early clinical adverse outcomes of either (1) graft-related death, (2) need for graft resection, (3) delayed graft function requiring temporary dialysis, or (4) a serum creatinine level of ≥ 2.0mg/dL at three months post-KT, as well as to predict biopsy-confirmed acute tubular necrosis and acute rejection. Of 187 patients included, 77 (41.2%) had at least one early adverse clinical outcome. Tc-99m MAG3 RS was more predictive than Tc-99m DTPA RS, in terms of AUCROC, in three parameters including time to peak (0.754 vs. 0.516, p-value 0.0001), 20-min to peak ratio (0.762 vs. 0.651, p-value 0.006), and 20-min to 3-min ratio (0.823 vs. 0.699, p-value 0.0005). Acute tubular necrosis was better predicted by Tc-99m MAG3 RS while both were at best only modest in predicting acute rejection. Three parameters which, when obtained from Tc-99m MAG3 RS, had superior predictiveness compared with Tc-99m DTPA RS, including time to peak, 20-min to peak ratio, and 20-min to 3-min ratio.