RT Journal Article SR Electronic T1 Comparison of Cystatin C and β-Trace Protein Versus 99mTc-DTPA Plasma Sampling in Determining Glomerular Filtration Rate in Chronic Renal Disease JF Journal of Nuclear Medicine Technology JO J. Nucl. Med. Technol. FD Society of Nuclear Medicine SP 206 OP 213 DO 10.2967/jnmt.115.154799 VO 43 IS 3 A1 Aydin, Funda A1 Budak, Evrim Surer A1 Demirelli, Serkan A1 Oner, Ali Ozan A1 Korkmaz, Selen A1 Suleymanlar, Gultekin A1 Akbas, Halide A1 Davran, Fatih A1 Gungor, Firat YR 2015 UL http://tech.snmjournals.org/content/43/3/206.abstract AB Glomerular filtration rate (GFR) is the best indicator of renal function. The gold standard for GFR measurement is inulin clearance. However, its measurement is inconvenient, time-consuming, and costly. Thus, in both scientific studies and routine clinical practice nuclear medicine methods (99mTc-diethylenetriaminepentaacetic acid [99mTc-DTPA] and 51Cr-ethylenediaminetetraacetic acid [51Cr-EDTA]) are preferred, and they correlate strongly with inulin clearance. In addition, cystatin C and β-trace protein have also recently been used for this purpose. In the literature, however, data are limited about the clinical value of cystatin C and β-trace protein in GFR measurement in chronic renal disease (CRD), and the results have been inconclusive. In this study, we aimed to determine the efficiency of cystatin C and β-trace protein in the determination of GFR in CRD patients. Methods: Eighty-four patients with CRD were included in the study (59 men and 25 women; age range, 21–88 y; mean age, 61 y). GFR was calculated using the gold-standard 99mTc-DTPA 2-sample plasma sampling method (TPSM) and 2 alternative methods: a formula using cystatin C and a formula using β-trace protein. The correlation between TPSM and the cystatin C and β-trace protein methods was assessed, and Bland–Altman analysis was used to graph scatterplots of the differences at a confidence interval of 95% (mean difference ± 1.96 SDs). Results: GFRs calculated using both alternative methods correlated strongly with those calculated using the gold standard. However, the correlation was stronger for the cystatin C method than for the β-trace protein method, and neither method produced reliably consistent GFRs. Conclusion: This study demonstrated that cystatin C and β-trace protein do not reflect GFR with sufficient accuracy.