健常人における111In-DTPA-IgGの生体内分布と動態

We assessed the biodistribution of 111In-DTPA-IgG administered to volunteers with a pharmacokinetic analysis. Volunteers were injected with 80MBq of 111In-DTPA-IgG. 111In uptakes decreased with time in all organs except in liver and bone marrow. At 70 h after injection, 111In uptakes in the intestine was 1.0% ID, suggesting that 111In-DTPA-IgG would be feasible to detect inflammation located in the abdomen. Analysis of plasma by size-exclusion HPLC showed mainly one radioactivity peak of labeled IgG, suggesting that 111In-DTPA-IgG was stable in the blood. The blood clearance was fitted to a two-compartment equation with half-lives of 6.6±1.6 h and 35.5±2.0 h for T1/2α and T1/2β, respectively. Total urinary excretion averaged 12.0±0.9% dose/72h, suggesting that 111In-DTPA-IgG may be excreted slowly through the urinary system.