Radiation dose estimation of human organs for 177Lu-anti-EGFR-PAMAM complex

Background: nowadays, radiolabeled monoclonal antibodies (mabs) are satisfactorily used for the diagnosis and therapy of different types of cancers. in this study, the human absorbed dose of 177lu-cetuximab-pamam was estimated based on the biodistribution data in tumor-bearing mice. materials and methods: 177lu-dtpa-chxcetuximab-pamam was prepared after the conjugation of cetuximab to pamam nanoparticles and dtpa-chx to mab-pamam. the biodistribution of the labeled nanosystem was studied in the tumor-bearing nude mice up to 72 h after injection. the absorbed dose of human organs was calculated according to the animals’ data utilizing the radiation absorbed dose assessment resource (radar) and the relative mass extrapolation methods. results: the radiolabeled compound, prepared at the optimized conditions, had a radiochemical purity (rcp) of 99.6% ± 0.4% (p < 0.05). most of the activity was accumulated in the tumor site (10.14 ± 0.89; p < 0.05). the liver and the kidneys received the highest absorbed dose with 0.561 and 0.207 msv/mbq, respectively, which is lesser than the other monoclonal antibodies labeled with 177lu. conclusion: considering the special characteristics of 177lu-dtpa-chx-cetuximab -pamam, this radiolabeled nano-system can be considered as a safe and effective radiolabeled compound for treatment of egfr-expressing tumors.