This study assessed 99mTc-mercaptoacetyltriglycine (MAG3) for determination of renal transplant prognosis for recovery in patients with early postoperative dysfunction. The postulate tested was that good tracer extraction may imply high likelihood of recovery, while poor extraction may confer a poor prognosis.
Methods: A 2-min image acquired 1 min after MAG3 administration, named a cortical uptake phase (CUP) image, was visually analyzed according to standardized semiquantitative guidelines. Interpretation was expressed in tubular injury severity scores (TISS) that ranged from 1 (a normally functioning renal transplant) to 6 (a photopenic defect in place of renal transplant).
Results: The study analyzed 64 patients (35 men, 29 women, age 45.9 +/- 14 yr). All five patients with TISS of 6 or 5 lost the transplant. Only 1 of 10 patients with TISS of 4 lost the transplant. All patients with TISS of less than 4 recovered renal transplant function.
Conclusion: This study suggests that MAG3 scan (the CUP image specifically) is an accurate prognosticator in patients with early postoperative renal transplant dysfunction. Reproduction of these results in a larger population and other institutions is necessary before clinical implementation of this methodology.