Evaluation of [99mTc] liposomes as lymphoscintigraphic agents:: comparison with [99mTc] sulfur colloid and [99mTc] human serum albumin

This study investigates the use of [Tc-99m] liposomes for the detection of sentinel lymph nodes. A variety of [Tc-99m] liposome formulations were compared with common lymphoscintigraphic agents including [Tc-99m] regular-sulfur colloid (SC), [Tc-99m] 0.22 mu -filtered-SC, [Tc-99m] reduced heating time 0.22 mu -filtered-SC, and [Tc-99m] human serum albumin (HSA) in rabbits. Images were acquired for the first 60 minutes and at 24 hours, followed by tissue biodistribution study. All agents except [Tc-99m] regular SC demonstrated good migration from the injection site. Agents were retained in the popliteal node at 24 hours to varying degrees as follows: both [Tc-99m] filtered SC preparations > [Tc-99m] regular SC > [Tc-99m] liposomes > [Tc-99m] HSA. [Tc-99m] liposome imaging can be used to develop novel liposome compositions with improved lymph node diagnostic and drug delivery characteristics. (C) 2001 Elsevier Science Inc. All rights reserved.