T K Johnson1, D McClure, S McCourt. 1. Department of Radiology, University of Colorado Health Sciences Center, Denver 80262, USA. tim.johnson@uchsc.edu
Abstract
UNLABELLED: The MABDOSE software represents a general tool to assess internal radiation dose. A suite of tests are described that validate the dosimetry system's implementation. METHODS: The validation suite is divided among tests that verify target digitalization, tumor digitalization and organ replacement, cumulated activity calculation, random number generation, radiation transport, and dose calculation. RESULTS: A comparison between Reference Man organ volumes and MABDOSE organ volumes at (5 mm)3 resolution demonstrates volume correspondence within 10% save for ten organs having dimensions smaller than the target lattice resolution. An accounting of normal organ volume replaced by an arbitrary tumor volume indicates mass is conserved. A comparison between cumulated activities generated by MABDOSE and solutions obtained analytically demonstrates exact correspondence for curve-fitting algorithms. For mathematical modeling algorithms, cumulated activity solutions converge to their correct values provided sufficient data of high precision are input, accompanied by reasonable initial estimates of rate constants. A comparison of MABDOSE results with the MIRD 3 report demonstrates good agreement (<8% difference) in absorbed fractions for spheres at energies from 20 keV to 2.75 MeV. A comparison of MABDOSE results with the Cristy-Eckerman report demonstrates marginal agreement (specific absorbed fractions within a factor of 2 for all Reference Man organs) at simulation energies of 20, 50, and 100 keV. Lack of exact correspondence is attributed to volume digitalization errors, and to differences in cross-section libraries, interpolation schemes between cross-section data points, and random number generators. Finally, the doses reported by MABDOSE correspond to the correct algebraic combination of paired cumulated activities and "S" values. CONCLUSIONS: The MABDOSE program has been validated as a general purpose computation tool for use in internal radionuclide dosimetry.
UNLABELLED: The MABDOSE software represents a general tool to assess internal radiation dose. A suite of tests are described that validate the dosimetry system's implementation. METHODS: The validation suite is divided among tests that verify target digitalization, tumor digitalization and organ replacement, cumulated activity calculation, random number generation, radiation transport, and dose calculation. RESULTS: A comparison between Reference Man organ volumes and MABDOSE organ volumes at (5 mm)3 resolution demonstrates volume correspondence within 10% save for ten organs having dimensions smaller than the target lattice resolution. An accounting of normal organ volume replaced by an arbitrary tumor volume indicates mass is conserved. A comparison between cumulated activities generated by MABDOSE and solutions obtained analytically demonstrates exact correspondence for curve-fitting algorithms. For mathematical modeling algorithms, cumulated activity solutions converge to their correct values provided sufficient data of high precision are input, accompanied by reasonable initial estimates of rate constants. A comparison of MABDOSE results with the MIRD 3 report demonstrates good agreement (<8% difference) in absorbed fractions for spheres at energies from 20 keV to 2.75 MeV. A comparison of MABDOSE results with the Cristy-Eckerman report demonstrates marginal agreement (specific absorbed fractions within a factor of 2 for all Reference Man organs) at simulation energies of 20, 50, and 100 keV. Lack of exact correspondence is attributed to volume digitalization errors, and to differences in cross-section libraries, interpolation schemes between cross-section data points, and random number generators. Finally, the doses reported by MABDOSE correspond to the correct algebraic combination of paired cumulated activities and "S" values. CONCLUSIONS: The MABDOSE program has been validated as a general purpose computation tool for use in internal radionuclide dosimetry.
Authors: Lore Santoro; L Pitalot; D Trauchessec; E Mora-Ramirez; P O Kotzki; M Bardiès; E Deshayes Journal: EJNMMI Res Date: 2021-01-04 Impact factor: 3.138