Background and aim: Assessment of volume of distribution (VD) and half-life (T1/2) values during glomerular filtration rate (GFR) investigations is a useful quality control check. The aim of this study was to derive reference data for VD and T1/2 and also to provide reference data for GFR from studies performed using 99mTc-diethylenetriaminepentaacetic acid (99mTc-DTPA).
Methods: This was a retrospective study of 126 healthy potential kidney donors (age range 18–59 years). The GFR was evaluated from 99mTc-DTPA plasma clearance using the 2004 British Nuclear Medicine Society guidelines. The association between VD and body surface area (BSA) was assessed. T1/2 was correlated with age and GFR. The correlation between the Brochner-Mortensen-corrected GFR (BM-GFRCorr) and age was evaluated.
Results: The uncorrected VD value (l) was 10.1×BSA±40.6% (P<0.01). The corrected VD value (l) was 8.19×BSA±34.4% (P<0.01). In individuals under the age of 40 years, the mean T1/2 was 95.0 min±36.2%. In individuals aged 40 years and above, the T1/2 increased at a rate of 0.49 min/year (P=0.04); the T1/2 (min) was 9480×(1/BM-GFRCorr)±35.1% (P<0.01). In individuals younger than 40 years of age, the correlation between BM-GFRCorr and age was not statistically significant (P=0.45), and the mean GFR was 108 ml/min/1.73 m2±27.5%. In individuals aged 40 years and above, the BM-GFRCorr was 170−(1.55×age) ml/min/1.73 m2±36.7% (P<0.001).
Conclusion: Well-defined reference data for VD and T1/2 can be used for quality control checks in GFR investigations. In addition to these, reference data for GFR using 99mTc-DTPA have been defined. This will enhance the interpretation of adult 99mTc-DTPA GFR measurements.
aDepartment of Nuclear Medicine, Tygerberg Hospital, Stellenbosch University, Cape Town, South Africa
bImaging Physics Group, Department of Medical Physics, University Hospital Southampton NHS Foundation Trust, Southampton, UK
cDiscipline of Medical Radiation Sciences, Faculty of Health Science
dBrain and Mind Research Institute, University of Sydney, Sydney, Australia
Data were presented at the 10th congress of the WFNMB, Cape Town, South Africa, and have been published as an abstract in World J Nucl Med 2010; 9(Suppl 1):S-90.
Correspondence to Jennifer L. Holness, MBChB, FCNP (SA), MMed, Department of Nuclear Medicine, Tygerberg Hospital, Stellenbosch University, Private Bag X3, Tygerberg, 7505, South Africa Tel: +27 21 938 4265; fax: +27 21 938 4694; e-mail: firstname.lastname@example.org
Received March 19, 2013
Accepted June 28, 2013