Predictive value of renal transplant scintigraphy for the duration of delayed graft function


S. Benjamens, R.A. Pol, A.W.J.M. Glaudemans, S.P. Berger, R.H.J.A. Slart

Chair(s): dr. N.P. van der Kaaij

Thursday 9 march 2017

13:00 - 13:15h

Categories: Poster - Klinisch

Parallel session: Postersessie - Klinisch 3


Background:
Renal scintigraphy (RS) is a widely used test for the assessment of the transplanted kidney (KTX). As RS cannot reliably distinguish between rejection and acute tubular necrosis we questioned whether RS could predict the expected duration of delayed graft function (DGF) and thus help guide the timing of a renal biopsy. This study focused on RS results, quantitatively analyzed and qualitatively graded, related to the duration of DGF. Improving the predictive value and clinical applicability of qualitative and quantitative RS indices may result in a more reliable prediction of the   duration of early graft dysfunction, resulting in a reduction of the number of diagnostic biopsies and faster treatment.

Methods:
From 2000 to 2014, all post-KTX RS procedures performed in patients with early transplant dysfunction were included. The duration of DGF was defined as the number of days of dialysis-based and/or functional DGF. All RS procedures were performed using Technetium-99m mercaptoacetyltriglycine (MAG3) with an intravenous administration dose of 80 MBq and were reanalyzed for the purpose of this study. RS results were qualitatively graded and various quantitative indices (Retention to Uptake ratio (R20/3), Tubular Function Slope (TFS), corrected Tubular Extraction Rate (cTER), Uptake corrected for injected dose (MUC10)) were combined with a new index (Average upslope).

Results:
A total of 177 patients were included, the mean age (± SD) was 49 ± 14 years, 57% were male, 17% received transplant after living-(un)related KTX, 41% after donation after brain death, and 42% after donation after circulatory death. A total of 136 (77%) patients experienced DGF ≥7 days of which 96 (54%) ≥14 days. Qualitative grading for the prediction of DGF >7 days had sensitivity and specificity of respectively 88% and 70%. The quantitative indices with the most optimal results for the prediction of DGF≥7 days were cTER (73% sensitivity, 85% specificity), and Average upslope (68% sensitivity, 84% specificity).

Conclusions:
In conclusion, the qualitative RS-grading and the RS quantitative indices cTER and Average upslope seem accurate predictors of DGF duration, in particular for DGF > or < than 7 days post-transplantation. Analyses of RS allows the identification of patients in whom the duration of DGF is longer than predicted and thus may help in identifying the need and timing of renal biopsy after KTX.