Value of early diethylentriamine penta-acetic acid renograms in predicting late allograft outcomes.

BACKGROUND

Tc-99m-diethylentriamine penta-acetic acid (DTPA) renal scintigraphy is useful, noninvasive diagnostic tool for the management and follow-up of the transplanted kidney. There have not been any studies of the predictive value of DTPA renal scintigraphy for short- and long-term allograft functions. Our aim was to reveal the significance of different perfusion-uptake patterns observed on Tc-99m-DTPA renal scintigraphy for long-term graft outcomes.

METHODS

We retrospectively analyzed 59 renal transplanted children (30 male and 29 female). All patients were underwent DTPA on posttransplant day 7. Perfusion- and function-related parameters of DTPA (the ratio of peak perfusion counts to plateau counts [P:PL], the ratio of counts at peak perfusion to counts at peak uptake [P:U], and glomerular filtration rate [GFR] calculated using commercially available software) were studied. The mean P:PL and P:U calculated using the half-moon-shaped background region of interest. A renal time activity curve was generated for evaluate perfusion- and function-related parameters. The patterns were classified and the value of these early DTPA parameters in predicting long-term graft function was analyzed.

RESULTS

The mean age of patients was 16.69 ± 4.77 years. The mean posttransplant follow-up time was 3.5 ± 0.4 years. Thirty-nine patients received living-related donor allografts and the remaining 20 were from deceased donors. Thirteen children suffered ≥ 1 acute rejection episode. Eight patients lost their grafts during follow-up. Mean GFR value at year 3 was 80.61 ± 39.03 mL/1.73 m(2) BSA/min. There was a significant difference for mean creatinine values at year 3 between recipients with normal perfusion and function and normal P:PL with decreased P:U patterns in early DTPA (P < .05). The normal P:PL with decreased P:U pattern is associated with lowest GFR value at posttransplant year 3. There was also a significant difference for mean GFR values at year 3 between recipients with normal perfusion and function and acute tubular necrosis (P < .05). Acute rejection episodes and graft loss were mostly seen in recipient with a decreased P:PL with or without decreased P:U pattern in early DTPA. The decreased P:PL with or without decreased P:U pattern may be associated with high risk of acute rejection episodes and graft loss.

CONCLUSION

Posttransplant early perfusion uptake patterns observed on Tc-99m-DTPA renal scintigraphy can be used as a long-term prognostic marker of poor renal outcomes. This would permit an opportunity for early intervention.