@article {Hofman405, author = {Michael Hofman and David Binns and Val Johnston and Shankar Siva and Mick Thompson and Peter Eu and Marnie Collins and Rodney J. Hicks}, title = {68Ga-EDTA PET/CT Imaging and Plasma Clearance for Glomerular Filtration Rate Quantification: Comparison to Conventional 51Cr-EDTA}, volume = {56}, number = {3}, pages = {405--409}, year = {2015}, doi = {10.2967/jnumed.114.147843}, publisher = {Society of Nuclear Medicine}, abstract = {Glomerular filtration rate (GFR) can accurately be determined using 51Cr-ethylenediaminetetraacetic acid (EDTA) plasma clearance counting but is time-consuming and requires technical skills and equipment not always available in imaging departments. 68Ga-EDTA can be readily available using an onsite generator, and PET/CT enables both imaging of renal function and accurate camera-based quantitation of clearance of activity from blood and its appearance in the urine. This study aimed to assess agreement between 68Ga-EDTA GFR (68Ga-GFR) and 51Cr-EDTA GFR (51Cr-GFR), using serial plasma sampling and PET imaging. Methods: 68Ga-EDTA and 51Cr-EDTA were injected concurrently in 31 patients. Dynamic PET/CT encompassing the kidneys was acquired for 10 min followed by 3 sequential 3-min multibed step acquisitions from kidneys to bladder. PET quantification was performed using renal activity at 1{\textendash}2 min (PETinitial), renal excretion at 2{\textendash}10 min (PETearly), and, subsequently, urinary excretion into the collecting system and bladder (PETlate). Plasma sampling at 2, 3, and 4 h was performed, with 68Ga followed by 51Cr counting after positron decay. The level of agreement for GFR determination was calculated using a Bland{\textendash}Altman plot and Pearson correlation coefficient (PCC). Results: 51Cr-GFR ranged from 10 to 220 mL/min (mean, 85 mL/min). There was good agreement between 68Ga-GFR and 51Cr-GFR using serial plasma sampling, with a Bland{\textendash}Altman bias of -14 {\textpm} 20 mL/min and a PCC of 0.94 (95\% confidence interval, 0.88{\textendash}0.97). Of the 3 methods used for camera-based quantification, the strongest correlation was for plasma sampling{\textendash}derived GFR with PETlate (PCC of 0.90; 95\% confidence interval, 0.80{\textendash}0.95). Conclusion: 68Ga-GFR agreed well with 51Cr-GFR for estimation of GFR using serial plasma counting. PET dynamic imaging provides a method to estimate GFR without plasma sampling, with the additional advantage of enabling renal imaging in a single study. Additional validation in a larger cohort is warranted to further assess utility.}, issn = {0161-5505}, URL = {https://jnm.snmjournals.org/content/56/3/405}, eprint = {https://jnm.snmjournals.org/content/56/3/405.full.pdf}, journal = {Journal of Nuclear Medicine} }