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

Purpose

Renal scintigraphy (RS) with either technetium-99 m diethylene-triamine-pentaacetate (Tc-99 m DTPA) or technetium-99 m mercaptoacetyltriglycine (Tc-99 m 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 3 months of KT.

Methods

This retrospective study included patients who received KT then underwent both Tc-99 m DTPA and Tc-99 m 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 ≥ 2.0 mg/dL at three months post-KT, as well as to predict biopsy-confirmed acute tubular necrosis and acute rejection.

Results

Of 187 patients included, 77 (41.2%) had at least one early adverse clinical outcome. Tc-99 m MAG3 RS was more predictive than Tc-99 m DTPA RS, in terms of AUC_ROC, 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-99 m MAG3 RS while both were at best only modest in predicting acute rejection.

Conclusion

Three parameters which, when obtained from Tc-99 m MAG3 RS, had superior predictiveness compared with Tc-99 m DTPA RS, including time to peak, 20-min to peak ratio, and 20-min to 3-min ratio.

Prognostic value of dynamic renal scan with 99mTc-EC in patients with kidney transplantation: a prospective descriptive study

INTRODUCTION

Renal transplantation is the gold standard treatment for chronic kidney disease. Renal scintigraphy has been performed widely to evaluate postsurgical complications of transplantation, but there are little data regarding 99mTc-EC scintigraphy in kidney transplantation.

METHODS AND MATERIALS

This was a prospective descriptive study. All patients who underwent kidney transplantation and passed an uneventful postoperative period entered the study. Demographic characteristics, including age, gender, biochemical parameters before and after the transplantation and 99mTc-EC parameters including time to max, time to ½ max, slope from max to ½ max, upslope time interval and time to 2/3 max as well as episodes of rejection, were recorded. Patients were then followed up for 1 year at 3-, 6-, 9- and 12-month intervals.

RESULTS

Forty-one patients who underwent renal transplantation entered the study. Mean ± SD age of patients was 40.65 ± 12.84 years (min 17 and max 74 years). In total, 25% (10) of patients experienced one or two episodes of rejection and were hospitalized. Time of max, time of 1/2 max, time from max to 1/2 max, time of 2/3 max, time from max to 2/3 max and upslope time interval had a significant association with transplant rejection using a Cox regression model. With 1-min increase in time of max, the risk of rejection increased by 27% (hazard ratio = 1.27; CI, 1.03--1.56) and with 1-min increase in time of 1/2 max, the risk of rejection increased by 28% (hazard ratio = 1.28; CI, 1.14-1.45).

DISCUSSION

99mTc-EC renal scintigrahpy was able to predict kidney transplantation rejection in our patients. 99mTc-EC renal scintigrahpy is beneficial to evaluate transplant kidney function to prevent complications and helps close follow-up.