Comparison of simultaneous plasma clearance of 99mTc-DTPA and 51Cr-EDTA: can one tracer replace the other?. (3rd October 2019)

• Record Type: Journal Article
• Authors: Andersen, Trine B.; Jødal, Lars; Nielsen, Nikolaj S.; Petersen, Lars J.
• Is Part Of: Scandinavian journal of clinical & laboratory investigation. Volume 79:Number 7(2019)
• Page Start: 463
• Page End: 467
• Publication Date: 2019-10-03
• Subjects: GFR -- renal function -- 51Cr-EDTA -- 99mTcDTPA -- glomerular filtration rate -- plasma clearance; Clinical biochemistry -- Periodicals; Physiology, Pathological -- Periodicals; Physiology, Experimental -- Periodicals; Medicine -- Research -- Periodicals; Clinical medicine -- Periodicals; 616.0072
• DOI: 10.1080/00365513.2019.1658217
• Languages: English
• ISSNs: 0036-5513

Abstract

Abstract: Both 99m Tc-DTPA and 51 Cr-EDTA are widely used to determine glomerular filtration rate (GFR), but few direct comparative studies exist. The shortage of 51 Cr-EDTA makes a direct comparison highly relevant. The aim of the study was to investigate if there is any clinically relevant difference between plasma clearance of 99m Tc-DTPA and 51 Cr-EDTA. Patients ≥18 years of age referred for routine GFR measurement by 51 Cr-EDTA were prospectively enrolled. The two tracers (10 MBq 99m Tc-DTPA (CaNa3 -DTPA) and 2.5 MBq 51 Cr-EDTA) were intravenously injected at time zero. A standard 4-sample technique was applied with samples collected at 180, 200, 220 and 240 min, if the estimated GFR (eGFR) was ≥30 mL/min. A comparison of single-sample GFR based on the 200 min sample was also conducted. Fifty-six patients were enrolled in the study. All patients had an estimated GFR >30 mL/min/1.73 m 2 . No patients suffered from ascites or significant oedema. The mean 51 Cr-EDTA plasma clearance was 82 mL/min (range 16–226). The plasma clearances determined by the two methods were highly correlated ( r = 0.993). The plasma clearance was significantly higher when measured by 99m Tc-DTPA than by 51 Cr-EDTA ( p = 0.01), but the numerical difference was minimal (mean difference 1.4 mL/min; 95% limits of agreement (LOA) –6.6 to 9.4). The difference between the two methods was independent of the level of renal function. Similar results were found for one-sample GFR. No clinically relevant differences were found between the plasma clearance of 99m Tc-DTPA and that of 51 Cr-EDTA. Therefore, 99m Tc-DTPA can replace 51 Cr-EDTA when needed.