title: 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 plasma-clearance 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.
authors.affiliation: Department of Oncology and Nuclear Medicine, The Persian Gulf Tropical Medicine Research Center, Bushehr University of Medical Sciences, Boostan 19 Alley, 7514763448, imam Khomeini Street, Bushehr, Iran. assadipoya@yahoo.com
authors.forename: Majid
authors.initials: M
authors.lastname: Assadi
authors.forename: Mohammad
authors.initials: M
authors.lastname: Eftekhari
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Hozhabrosadati
authors.forename: Mohsen
authors.initials: M
authors.lastname: Saghari
authors.forename: Abdolali
authors.initials: A
authors.lastname: Ebrahimi
authors.forename: Iraj
authors.initials: I
authors.lastname: Nabipour
authors.forename: Mohammad Zaki
authors.initials: MZ
authors.lastname: Abbasi
authors.forename: Darab
authors.initials: D
authors.lastname: Moshtaghi
authors.forename: Moloud
authors.initials: M
authors.lastname: Abbaszadeh
authors.forename: Sakineh
authors.initials: S
authors.lastname: Assadi
mesh_terms: D000293:Adolescent; D000328:Adult; D003404:Creatinine / Q000097:blood*; D005260:Female; D015902:Gamma Cameras; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging; D007674:Kidney Diseases / Q000097:blood* / Q000000981:diagnostic imaging*; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D011866:Radioisotope Renography / Q000379:methods*; D019275:Radiopharmaceuticals; D012044:Regression Analysis; D016284:Technetium Tc 99m Pentetate
chemical_list: D019275:Radiopharmaceuticals; D003404:Creatinine; D016284:Technetium Tc 99m Pentetate