4-Dimensional dosimetry of 131I-NM404 using µPET/CT and Pinnacle™

Grudzinski et al.
University of Wisconsin, Madison, Wisconsin, USA
 |  04.02.2010


The purpose of this study was to determine the dosimetry of NM404 – a diapeuticTM agent we are developing for detection and treatment of a wide range of solid tumors – within a tumor bearing mouse using STRATOS (Systemic Targeted Radiotherapy Optimization Solution), a four dimensional dosimetry package from Pinnacle (Fitchburg, Wisconsin). Since the kinetics of NM404 are the same regardless of the attached iodine isotope, it is possible to predict the 131I-NM404 therapeutic tumor dosimetry based on the 124I-NM404 diagnostic PET data. Using an Inveon PET•CT scanner, it is possible to track 124I-NM404 throughout a rodent’s body and predict the dose limiting organs. The STRATOS plug-in takes the 124I-NM404 data and simulates the physics of 131I so that therapeutic dosimetry can be computed for treatment planning based on the dose limiting organ. To our knowledge, this is the first report of using dynamic µPET•CT to accurately predict radiation dosimetry of a systemically administered radiopharmaceutical agent. This demonstrates the feasibility of performing individualized patient specific dosimetry utilizing diagnostic PET•CT.