Biodistribution and absorbed radiation dose estimates of Tc-99m-labeled dimercaptopropionyl human serum albumin

The use of Tc-99m-labeled red blood cells (RBC) for the evaluation of left ventricular function using equilibrium-gated blood-pool imaging suffers fro m several problems and potential risks. In this study, we estimated the abs orbed radiation dose of Tc-99m-labeled dimercaptopropionyl human serum albu min (DMP-HSA) as a potential alternative to Tc-99m-RBC. Methods: After the administration of Tc-99m-DMP-HSA, whole-body imaging was performed Up to 48 h after injection in five volunteers. The heart contents, liver and remain der of the body were used as source organs. Multicompartment modeling of th e biodistribution was performed and absorbed radiation dose estimates for T c-99m-DMP-HSA were obtained using the Medical Internal Radiation Dose (MIRD ) calculation. Results: Residence times of 0.62 and 0.43 h were obtained fo r the heart contents and liver. respectively. Radiation dose estimates yiel ded an effective dose of 0.0055 mSv/MBq. Conclusion: 99mTc-DMP-HSA yielded absorbed radiation doses comparable with those of 99mTc-RBC. Therefore, the radiation properties of Tc-99m-DMP-HSA are such that it can be used for cl inical diagnostic studies.