A rapid method for the labeling of albumin microspheres with In-113 and In-111: concise communication

A rapid and simple method for preparing microspheres labeled with In-113m or In-111 is described. The procedure requires 10 min and gives labeling yields approaching 100%. Biodistribution studies in rats, mice, and dogs show the product to be biologically stable, with approximately 90% of the injected dose localized in the lung at 1 hr postinjection. The convenient production of In-113m or In-111 albumin microspheres provides an alternate radiopharmaceutical to complement or substitute for Tc-99m microspheres in lung perfusion imaging and other circulation studies.