99mTc-albumin can replace 125I-albumin to determine plasma volume repeatedly

TY - JOUR

T1 - 99mTc-albumin can replace 125I-albumin to determine plasma volume repeatedly

AU - Bonfils, Peter K

AU - Damgaard, Morten

AU - Stokholm, Knud H

AU - Nielsen, Steen L

PY - 2012/10

Y1 - 2012/10

N2 - Objective. Plasma volume assessment may be of importance in several disorders. The purpose of the present study was to compare the reliability of plasma volume measurements by technetium-labeled human serum albumin ( 99mTc-HSA) with a simultaneously performed plasma volume determination with iodine-labeled human serum albumin (125I-HSA). Materials and methods. In 15 healthy volunteers, simultaneous plasma volume measurements with 99mTc-HSA and 125I-HSA were performed after hour in the supine position. Blood samples were obtained 10, 15, 20, and 30 minutes after the injection for accurate retropolation from the plasma counts to time zero to correct for leakage of the isotopes from the circulation. Results. The mean difference (bias) between plasma volume measured with 125I-albumin and 99mTc-albumin was 8 ml (0.1 ml/kg) with limits of agreement (bias ±1.96 SD) ranging from 181196 ml (-2.32.5 ml/kg). The tracer disappearance rate was significantly higher with 99mTc-albumin (-23.1±7.1%/h) than with 125I-albumin (-6.7±3.6%/h) (p <0.001). Conclusion. This study demonstrates that 99mTc-HSA can replace 125I-HSA for single measurements of plasma volume in healthy volunteers. It needs to be emphasized however, that repeated blood sampling for 1/2 hour after injection of the tracer is required to correct for the disappearance of 99mTc and 99mTc-HSA from the circulation.

AB - Objective. Plasma volume assessment may be of importance in several disorders. The purpose of the present study was to compare the reliability of plasma volume measurements by technetium-labeled human serum albumin ( 99mTc-HSA) with a simultaneously performed plasma volume determination with iodine-labeled human serum albumin (125I-HSA). Materials and methods. In 15 healthy volunteers, simultaneous plasma volume measurements with 99mTc-HSA and 125I-HSA were performed after hour in the supine position. Blood samples were obtained 10, 15, 20, and 30 minutes after the injection for accurate retropolation from the plasma counts to time zero to correct for leakage of the isotopes from the circulation. Results. The mean difference (bias) between plasma volume measured with 125I-albumin and 99mTc-albumin was 8 ml (0.1 ml/kg) with limits of agreement (bias ±1.96 SD) ranging from 181196 ml (-2.32.5 ml/kg). The tracer disappearance rate was significantly higher with 99mTc-albumin (-23.1±7.1%/h) than with 125I-albumin (-6.7±3.6%/h) (p <0.001). Conclusion. This study demonstrates that 99mTc-HSA can replace 125I-HSA for single measurements of plasma volume in healthy volunteers. It needs to be emphasized however, that repeated blood sampling for 1/2 hour after injection of the tracer is required to correct for the disappearance of 99mTc and 99mTc-HSA from the circulation.

KW - Female

KW - Humans

KW - Male

KW - Middle Aged

KW - Plasma Volume

KW - Radiopharmaceuticals

KW - Reproducibility of Results

KW - Serum Albumin, Radio-Iodinated

KW - Technetium Tc 99m Aggregated Albumin

U2 - 10.3109/00365513.2012.688856

DO - 10.3109/00365513.2012.688856

M3 - Journal article

C2 - 22646079

SN - 0036-5513

VL - 72

SP - 447

EP - 451

JO - Scandinavian Journal of Clinical & Laboratory Investigation

JF - Scandinavian Journal of Clinical & Laboratory Investigation

IS - 6

ER -