Comparison of methods for determination of glomerular filtration rate: low and high-dose Tc-99m-DTPA renography, predicted creatinine clearance method, and plasma sample method

Abstract

The gamma camera uptake method with Tc-99m-DTPA (diethylenetriaminepentaacetic acid) is a simple method for determination of glomerular filtration rate (GFR), and is less time-consuming than other methods, but its diagnostic accuracy is debated. Gate's method (low-dose; LD), the high-dose method (HD), the predicted-clearance method, and the plasmaclearance method with Tc-99m-DTPA are compared in this study. We also performed GFR measurement and diuretic renography simultaneously. Tc-99m DTPA renography was performed in 36 patients aged 18-72 years with a wide range of renal function (serum creatinine 1.37 ± 0.49 mg/dl). GFR was determined by four methods: the gamma camera uptake method with low-dose Tc-99m DTPA (Gates, LD); the gamma camera uptake method with high-dose Tc-99m DTPA (HD); the predicted creatinine clearance method (Cockcroft-Gualt, CG); and the plasma sample clearance (PSC) method using a mono-exponential curve. The PSC method was chosen as reference. The regression equations for the CG, Gates (low-dose), and HD methods against the PSC method were 28.68 + 0.80X (r = 0.72; P value \ 0.0001, RMSE = 21.65 ml/min/ 1.73 m 2 ), 6.19 + 0.79X (r = 0.90; P value \ 0.0001, RMSE = 10.64 ml/min/1.73 m 2 ), and 6.53 + 0.88X (r = 0.93; P value \ 0.0001, RMSE = 9.35 ml/min/ 1.73 m 2 ), respectively. In comparison with determination of GFR by the PSC method, the CG method tended to overestimate GFR while, perversely, the LD and HD methods tended to underestimate GFR. The three methods were in agreement with the PSC method but the high-dose GFR method resulted in less error in estimation of GFR. Furthermore, GFR measurement and diuretic renography could be performed at the same time when the high-dose method was used. Because of the low cost and negligible radiation burden, this method might be preferred for routine practice in nuclear medicine.

Glomerular filtration rate (GFR) estimated from serum creatinine predicts total (urine and peritoneal) creatinine clearance in patients on peritoneal dialysis

“…In agreement with most of the previous comparative analyses [11,12] that showed that the classical CCrCG equation overestimated glomerular filtration and also residual renal function, we also found CCrCG equation overestimated clearance measured by [cGFR ? PCcr].…”

Performance of the Cockcroft-Gault and MDRD equations in adult Nigerians with chronic kidney disease

“…This recommendation has been validated in several Caucasian and African-American patient populations [13][14][15][16][17][18][19][20][21][22]. Few reports exist among native Africans validating prediction equations in the prediction of the GFR [23][24][25].…”

Comparison between GFR Values Obtained by CG-formula and DTPA Renography in Different Renal Disorders

“…And the correlation graph (Graph 1) also shows good linear relationship. Comparing the various methods by determination of GFR by99mTc DTPA by Gate's renography and predicted creatinine clearance by the Cockroft Gault (CG) equation in 36 patients, Assadi et al concluded that Gates method is more precise than the CG method [5] . Similarly Peterson et al [6] observed that 99mTc renography is more accurate than 24 hrs creatinine clearance and is acceptable for clinical use in patients with reduced renal function.…”