99mTc-mercaptoacetyl Triglycine Renography to Monitor Renal Transplant Function Among Kidneys from Donors After Cardiac Death

99mTc-mercaptoacetyltriglycine Cortical Renography Predicts Outcomes in Adult Living Donor Renal Transplant Recipients

BACKGROUND

The clinical utility of ^99mTc-mercaptoacetyltriglycine cortical renography for the prediction of graft function in kidney transplant recipients has been unknown.

METHODS

We retrospectively reviewed post-transplant cortical renograms in 40 kidney transplant recipients. We analyzed the correlation between T_1/2 (elimination half-life) and graft function (measured-to-expected glomerular filtration rate [GFR]) 1 week, and 1, 3, and 6 months post operation compared with whole-kidney renograms.

RESULTS

Delayed drainage (T_1/2 > 11 minutes) was observed in 22 recipients (55%). T_1/2 and postoperative GFR ratio were inversely correlated (1 week: R² = 0.317, P = .0002; 1 month: R² = 0.206, P = .003; 3 months: R² = 0.117, P = .031; 6 months: R² = 0.161, P = .010). Recipients with delayed drainage had a significantly lower GFR ratio than those with normal drainage 1 week (median, 0.93 vs 1.32; P = .001), 1 month (median, 1.65 vs 2.23; P = .0010), 3 months (median, 1.55 vs 2.17; P = .041), and 6 months (median, 1.67 vs 2.34; P = .018) post operation, respectively. Whole-kidney renograms failed to discriminate recipients with lower GFR ratio at 1, 3, and 6 months.

CONCLUSIONS

T_1/2 in post-transplant cortical renography was inversely correlated with early graft function and may predict early post-transplant graft function.

Limited clinical value of two consecutive post-transplant renal scintigraphy procedures

Objectives

Duration of delayed graft function (DGF) and length of hospital stay (LOS) are outcomes of interest in an era that warrants increased efficacy of transplant care whereas renal allografts originate increasingly from marginal donors. While earlier studies investigate the predictive capability of a single renal scintigraphy, this study focuses on the value for both DGF duration and LOS of consecutively performed scintigraphies.

Methods

From 2011 to 2014, renal transplant recipients referred for a Tc-99m MAG3 renal scintigraphy were included in a single-center retrospective study. Primary endpoints were DGF duration and LOS. Both the first (≤ 3 days) and second scintigraphies (3–7 days after transplantation) were analyzed using a 4-grade qualitative scale and quantitative indices (TFS, cTER, MUC10, average upslope).

Results

We evaluated 200 first and 108 (54%) consecutively performed scintigraphies. The Kaplan-Meier curves for DGF duration and qualitative grading of the first and second scintigraphy showed significant differences between the grades (p < 0.01). The Kaplan-Meier curve for the delta grades between these procedures (lower, equal, or higher grade) did not show significant differences (p = 0.18). Multivariate analysis showed a significant association between the qualitative grades, from the first and second scintigraphy, and DGF duration, HR 1.8 (1.4–2.2, p < 0.01) and 2.8 (1.8–4.3, p < 0.01), respectively.

Conclusions

Qualitative grades of single renal scintigraphies, performed within 7 days after transplantation, can be used to make a reliable image-guided decision on the need for dialysis and to predict LOS. A consecutive renal scintigraphy, however, did not show an additional value in the assessment of DGF.

Key Points

• Post-transplant renal scintigraphy procedures provide information to predict delayed graft function duration and length of hospital stay.

• Performing two consecutive renal scintigraphy procedures within 1 week after transplantation does not strengthen the prediction of delayed graft function duration and length of hospital stay.

• Single renal scintigraphy procedures can be used to provide clinicians and patients with a reliable indication of the need for dialysis after transplantation and the expected duration of hospitalization.

Electronic supplementary material

The online version of this article (10.1007/s00330-019-06334-1) contains supplementary material, which is available to authorized users.

Can transplant renal scintigraphy predict the duration of delayed graft function? A dual center retrospective study

Introduction

This study focused on the value of quantitatively analyzed and qualitatively graded renal scintigraphy in relation to the expected duration of delayed graft function after kidney transplantation. A more reliable prediction of delayed graft function duration may result in a more tailored and patient-specific treatment regimen post-transplantation.

Methods

From 2000 to 2014, patients with early transplant dysfunction and a Tc-99m MAG3 renal scintigraphy, within 3 days post-transplantation, were included in a dual center retrospective study. Time-activity curves of renal scintigraphy procedures were qualitatively graded and various quantitative indices (R20/3, TFS, cTER, MUC10) were combined with a new index (Average upslope). The delayed graft function duration was defined as the number of days of dialysis-based/functional delayed graft function.

Results

A total of 377 patients were included, with a mean age (± SD) of 52 ± 14 years, and 58% were male. A total of 274 (73%) patients experienced delayed graft function≥ 7 days. Qualitative grading for the prediction of delayed graft function≥ 7 days had a sensitivity and specificity of respectively 87% and 65%. The quantitative indices with the most optimal results were cTER (76% sensitivity, 72% specificity), and Average upslope (75% sensitivity, 73% specificity).

Conclusions

Qualitative renal scintigraphy grading and the quantitative indices cTER and Average upslope predict delayed graft function ≥ 7 days with a high sensitivity. This finding may help to support both clinicians and patients in managing early post-operative expectations. However, the specificity is limited and thus renal scintigraphy does not reliably help to identify patients in whom the course of delayed graft function is longer than anticipated.