Modification of a two blood sample method used for measurement of GFR with 99mTc-DTPA
Abstract
BACKGROUND
Measurements of GFR may be performed with a slope/intercept method (S/I), using only two blood samples taken in strictly defined time points. The aim of the study was to modify this method in order to extend time intervals suitable for blood sampling. Modification was based on a variation of a Russel et al. model parameter, selection of time intervals suitable for blood sampling and assessment of uncertainty of calculated results.
MATERIAL AND METHODS
Archived values of GFR measurements of 169 patients with different renal function, from 5.5 to 179 mL/min, calculated with a multiple blood sample method were used. Concentrations of a radiopharmaceutical in consecutive minutes, from 60th to 190th after injection, were calculated theoretically, using archived parameters of biexponential functions describing a decrease in 99mTc-DTPA concentration in blood plasma with time. These values, together with injected activities, were treated as measurements and used for S/I clearance calculations. Next, values of S/I clearance were compared with the multiple blood sample method in order to calculate suitable values of exponent present in a Russel’s model, for every combination of two blood sampling time points. A model was considered accurately fitted to measured values when SEE ≤ 3.6 mL/min. Assessments of uncertainty of obtained results were based on law of error superposition, taking into account mean square prediction error and also errors introduced by pipetting, time measurement and stochastic radioactive decay.
RESULTS
The accepted criteria resulted in extension of time intervals suitable for blood sampling to: between 60 and 90 minutes after injection for the first sample and between 150 and 180 minutes for the second sample. Uncertainty of results was assessed as between 4 mL/min for GFR = 5–10 mL/min and 8 mL/min for GFR = 180 mL/min.
CONCLUSIONS
Time intervals accepted for blood sampling fully satisfy nuclear medicine staff and ensure proper determination of GFR. Uncertainty of results is entirely acceptable and for high GFR values even comparable with uncertainty of multi-sample measurements.
Keywords: GFRtwo-sample methodslope/intercept GFR
References
- Cockcroft DW, Gault MH. Prediction of creatinine clearance from serum creatinine. Nephron. 1976; 16(1): 31–41.
- Parker RA, Bennett WM, Porter GA. Clinical estimation of creatinine clearance without urine collection. Dialysis and Transplantation. 1980; 9: 251–2.
- Gault MH, Longerich LL, Harnett JD, et al. Predicting glomerular function from adjusted serum creatinine. Nephron. 1992; 62(3): 249–256.
- Levey AS, Bosch JP, Lewis JB, et al. A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Modification of Diet in Renal Disease Study Group. Ann Intern Med. 1999; 130(6): 461–470.
- Levey AS, Stevens LA, Schmid CH, et al. CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration). A new equation to estimate glomerular filtration rate. Ann Intern Med. 2009; 150(9): 604–612.
- Levey AS. Measurement of renal function in chronic renal disease. Kidney Int. 1990; 38(1): 167–184.
- Perrone RD, Madias NE, Levey AS. Serum creatinine as an index of renal function: new insights into old concepts. Clin Chem. 1992; 38(10): 1933–1953.
- Klahr S, Levey AS, Beck GJ, et al. The effects of dietary protein restriction and blood-pressure control on the progression of chronic renal disease. Modification of Diet in Renal Disease Study Group. N Engl J Med. 1994; 330(13): 877–884.
- Sapirstein LA, Vidt DG, Mandel MJ, et al. Volumes of distribution and clearances of intravenously injected creatinine in the dog. Am J Physiol. 1955; 181(2): 330–336.
- Brien TG, O'Hagan R, Muldowney FP. Chromium -51- EDTA in the determination of glomerular filtration rate. Acta Radiol Ther Phys Biol. 1969; 8(6): 523–529.
- Chantler C, Barratt TM. Estimation of glomerular filtration rate from plasma clearance of 51-chromium edetic acid. Arch Dis Child. 1972; 47(254): 613–617.
- Sambataro M, Thomaseth K, Pacini G, et al. Plasma clearance rate of 51Cr-EDTA provides a precise and convenient technique for measurement of glomerular filtration rate in diabetic humans. J Am Soc Nephrol. 1996; 7(1): 118–127.
- Chantler C, Garnett ES, Parsons V, et al. Glomerular filtration rate measurement in man by the single injection methods using 51Cr-EDTA. Clin Sci. 1969; 37(1): 169–180.
- Farmer CD, Tauxe WN, Maher FT, et al. Measurement of renal function with radioiodinated diatrizoate and omicron-iodohippurate. Am J Clin Pathol. 1967; 47(1): 9–16.
- Russell CD, Bischoff PG, Kontzen FN, et al. Measurement of glomerular filtration rate: single injection plasma clearance method without urine collection. J Nucl Med. 1985; 26(11): 1243–1247.
- Bodei L, Kidd M, Paganelli G, et al. Long-term tolerability of PRRT in 807 patients with neuroendocrine tumours: the value and limitations of clinical factors. Eur J Nucl Med Mol Imaging. 2015; 42(1): 5–19.
- Sabet A, Ezziddin K, Pape UF, et al. Accurate assessment of long-term nephrotoxicity after peptide receptor radionuclide therapy with 177Lu-octreotate. Eur J Nucl Med Mol Imaging. 2013; 41(3): 505–510.
- Geist BK, Diemling M, Staudenherz A. Glomerular Filtration Rate and Error Calculation Based on the Slope-Intercept Method with Chromium-51 Ethylenediaminetetraacetic Acid via a New Clinical Software: GFRcalc. Med Princ Pract. 2016; 25(4): 368–373.
- Brøchner-Mortensen J. Routine methods and their reliability for assessment of glomerular filtration rate in adults, with special reference to total [51Cr]EDTA plasma clearance. Dan Med Bull. 1978; 25(5): 181–202.
- Hagstam KE, Nordenfelt I, Svensson L, et al. Comparison of different methods for determination of glomerular filtration rate in renal disease. Scand J Clin Lab Invest. 1974; 34(1): 31–36.
- Tepe PG, Tauxe WN, Bagchi A, et al. Comparison of measurement of glomerular filtration rate by single sample, plasma disappearance slope/intercept and other methods. Eur J Nucl Med. 1987; 13(1): 28–31.
- Dias AH, Pintão S, Almeida P, et al. Comparison of GFR calculation methods: MDRD and CKD-EPI vs. (99m)Tc-DTPA tracer clearance rates. Scand J Clin Lab Invest. 2013; 73(4): 334–338.
- Surma MJ. Comparison of accuracy and precision of three methods of GFR determination. Eur J Nucl Med Mol Imag. 2009; 36(S2): 438.
- Haycock GB, Schwartz GJ, Wisotsky DH. Geometric method for measuring body surface area: a height-weight formula validated in infants, children, and adults. J Pediatr. 1978; 93(1): 62–66.
