99mTc-DTPA volume of distribution, half-life and glomerular filtration rate in normal adults

Abstract

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 Tc-DTPA have been defined. This will enhance the interpretation of adult Tc-DTPA GFR measurements.

An electronic technetium-99m-diethylenetriaminepentaacetic acid glomerular filtration rate spreadsheet with novel embedded quality assurance features

“…QC on the basis of physiologic metrics is difficult in a heterogenous clinic such of ours, consisting of patient populations ranging from healthy, potential kidney donors to patients with severe renal dysfunction. As an example, errors between volume of distribution estimated using BSA and Brochner–Mortensen corrected GFR and BSA alone have been proposed for QC 23, but had 24.0% variability, which is too large to be of clinical utility as a QC measure 14. This conclusion is consistent with those of McMeekin et al .…”

“…Other physiologic parameters could be considered for QC testing, including volume of distribution, extra-cellular volume, and time to 50% washout ( T 1/2 ) 4,23. We did not include these error measures as variabilities, even in normal populations of potential donors, were relatively high compared with the physics-based quality metrics described in this work, and certainly were outside of ‘normal’ values in patients with renal disease.…”

Glomerular Filtration Rate in Healthy Living Potential Kidney Donors: A Meta-Analysis Supporting the Construction of the Full Age Spectrum Equation

“…Table 1 gives an overview of the studies and the way we obtained mean GFR, SD and numbers for men and women from the 12 selected publications [6,[9][10][11][12][13][14][15][16][24][25][26] . Table 2 gives a detailed overview of the data for mean GFR, SD and numbers of men and women per age group, as we extracted them from these publications.…”

“…Finally, the comparison between age groups 50-60 and 60-70 years (for all studies, except for Vervoort et al [24] , Hamilton et al [10] , Berg [14] and Holness et al [16] who did not have kidney donors in the last age group) gives an overall effect size of 0.55 with 95% CI of 0.42-0.67 (p < 0.0001) corresponding to a difference of 8.2 ml/ min/1.73 m 2 indicating that the decrease goes on at the same rate.…”

Measuring extracellular volume fraction by MRI: First verification of values given by clinical sequences

“…The criteria that need to be fulfilled for this to be true are (1) that the radiolabeled compound (99mTc‐DTPA) need to distribute in the predicted manner (i.e., extracellularly) and (2) the activity recorded must reflect the amount of isotope and not be influenced by self‐absorption or the shape of the sample. It has been shown, both for 99mTc‐DTPA and Gd‐DTPA, that the distribution is extracellular, and this fact is used in, for example, viability imaging in CMR . As for self‐absorption, the half‐value layer of tissue for 99mTc seems to be around 4 cm which, if approximating the tissue to a cube with a density of 1 g/cm3, would correspond to a biopsy weighing 64 g .…”