Development of a validation imaging dataset for Molecular Radiotherapy dosimetry multicenter intercomparison exercises based on anthropomorphic phantoms. (May 2023)

• Record Type: Journal Article
• Authors: Robinson, Andrew P.; Calvert, Nick; Tipping, Jill; Denis-Bacelar, Ana M.; Ferreira, Kelley M.; Lassmann, Michael; Tran-Gia, Johannes
• Is Part Of: Physica medica. Volume 109(2023)
• Publication Date: 2023-05
• Subjects: MRT dosimetry -- Phantom -- Lu-177 -- Validation; Medical physics -- Periodicals; Biophysics -- Periodicals; Biophysics -- Periodicals; Imagerie médicale -- Périodiques; Radiothérapie -- Périodiques; Rayons X -- Sécurité -- Mesures -- Périodiques; Physique -- Périodiques; Médecine -- Périodiques; 610.153
• DOI: 10.1016/j.ejmp.2023.102583
• Languages: English
• ISSNs: 1120-1797

Abstract

Abstract: Validation of a Molecular Radiotherapy (MRT) dosimetry system requires imaging data for which an accompanying "ground truth" pharmacokinetic model and absorbed dose calculation are known. Methods: We present a methodology for production of a validation dataset for image based 177 Lu dotatate dosimetry calculations. A pharmacokinetic model is presented with activity concentrations corresponding to common imaging timepoints. Anthropomorphic 3D printed phantoms, corresponding to the organs at risk, have been developed to provide SPECT/CT and Whole Body imaging with known organ activities corresponding to common clinical timepoints. Results: Results for the accuracy of phantom filling reproduce the activity concentrations from the pharmacokinetic model for all timepoints and organs within measurement uncertainties, with a mean deviation of 0.6(8)%. The imaging dataset, ancillary data and phantoms designs are provided as a source of well characterized input data for the validation of clinical MRT dosimetry systems. Conclusions: The combination of pharmacokinetic modelling with the use of anthropomorphic 3D printed phantoms are a promising procedure to provide data for the validation of Molecular Radiotherapy Dosimetry systems, allowing multicentre comparisons. Highlights: An imaging dataset for validation of a Molecular Radiotherapy dosimetry system has been produced. A method for producing a dataset representing a ground truth PK model is presented. PK model reproduced all time points and organs within measurement uncertainties. Dataset is available allowing institutions to compare calculated dosimetry values.