Internal Dosimetry Modelling for 89Zr-labelled Chimeric Monoclonal Antibody U36 Based on Real Clinical Results

Abstract

The dynamic of 89Zr-labelled chimeric monoclonal antibody U36 after injection into the human body is modelled based on real clinical results. Results for nine patients (women) from published work is used to create a simple biokinetic model. Cumulative 89Zr Activity in organs and tissues per Bq of administered Activity is calculated with the WinAct program. For the most organs receiving the highest radiation exposure, average absorbed doses were estimated with IDAC 2.1 software. The organs exhibiting the highest dose for adult women were the red bone marrow, lungs, liver, spleen, kidneys, and thyroid (at 1.21,0.837, 0.811, 0.759, 0.745, and 0.411 mGy/MBq, respectively), when the injection was associated with monoclonal antibodies. The results from a new modified biokinetic and modelled calculations are compared with the published experimental diagnostic results conducted in real patients and with given results by OLINDA software, which are in good agreement. Based on real clinical results, the recommended value of blood removing biological time is 65 h for Zr-89 labelled with cMab-U36. © 2020 American Institute of Physics Inc. All rights reserved.