Technetium-99m haemaccel: a new lymphoscintigraphic agent.

Haemaccel, a denatured gelatin polymer with average molecular weight of 35,000, was labeled with Tc-99m and evaluated in rats and rabbits. The labeling efficiency was consistently higher than 85%. Tc-99m haemaccel (200 microCi in 0.05 ml) was injected intradermally into the hind footpads of rats lightly anaesthetized with diethyl ether vapour. Using a gamma camera, static images of the anterior view were obtained at various time intervals after injection. The images obtained demonstrated good localization of Tc-99m haemaccel in regional lymph nodes. In rats, about 3% of the injected dose was trapped in the node, and 48% remained at the injection site at 4 h after injection. In rabbits, good-quality images of lymph nodes and lymphatic channels of the hind legs were obtained within 15 min after intradermal injection of Tc-99m haemaccel. Tc-99m haemaccel showed fast migration from the injection site, good accumulation in the lymph nodes, and good visualization of lymphatic channels. Hence, it has a potential application in lymphoscintigraphy.