Assadi Majid, Eftekhari Mohammad, Hozhabrosadati Mehrdad, Saghari Mohsen, Ebrahimi Abdolali, Nabipour Iraj, Abbasi Mohammad Zaki, Moshtaghi Darab, Abbaszadeh Moloud, Assadi Sakineh
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.
Int Urol Nephrol. 2008;40(4):1059-65. doi: 10.1007/s11255-008-9446-4. Epub 2008 Aug 9.
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.
采用锝-99m-二乙三胺五乙酸（Tc-99m-DTPA）的γ相机摄取法是一种测定肾小球滤过率（GFR）的简单方法，且比其他方法耗时少，但其诊断准确性存在争议。本研究比较了Gate法（低剂量；LD）、高剂量法（HD）、预测清除率法和采用Tc-99m-DTPA的血浆清除率法。我们还同时进行了GFR测量和利尿肾图检查。对36例年龄在18至72岁、肾功能范围广泛（血清肌酐1.37±0.49mg/dl）的患者进行了Tc-99m DTPA肾图检查。通过四种方法测定GFR：采用低剂量Tc-99m DTPA的γ相机摄取法（Gate，LD）；采用高剂量Tc-99m DTPA的γ相机摄取法（HD）；预测肌酐清除率法（Cockcroft-Gault，CG）；以及使用单指数曲线的血浆样本清除率（PSC）法。选择PSC法作为参考。CG法、Gate法（低剂量）和HD法相对于PSC法的回归方程分别为28.68 + 0.80X（r = 0.72；P值<0.0001，均方根误差[RMSE]=21.65ml/min/1.73m²）、6.19 + 0.79X（r = 0.90；P值<0.0001，RMSE = 10.64ml/min/1.73m²）和6.53 + 0.88X（r = 0.93；P值<0.0001，RMSE = 9.35ml/min/1.73m²）。与通过PSC法测定GFR相比，CG法倾向于高估GFR，而反常的是，LD法和HD法倾向于低估GFR。这三种方法与PSC法一致，但高剂量GFR法在GFR估计中产生的误差较小。此外，当使用高剂量法时，可以同时进行GFR测量和利尿肾图检查。由于成本低且辐射负担可忽略不计，该方法可能是核医学常规实践中的首选方法。
