Pharmacokinetics and biodistribution of 111In- and 177Lu-labeled J591 antibody specific for prostate-specific membrane antigen: Prediction of 90Y-J591 radiation dosimetry based on 111In or 177Lu?
111In- and 177Lu-labeled J591 antibodies have similar plasma and whole-body clearance kinetics. The net retention of 111In activity by lung, liver, and spleen is slightly higher compared with that with 177Lu. These results justify using 111In as a chemical and biologic surrogate for 90Y. However, the radiation dose to the liver may be overestimated by about 25% based on 111In data. In addition, the data also suggest that 177Lu may be a potential alternative for estimating the pharmacokinetics and biodistribution of 90Y-labeled radiopharmaceuticals.