VIDA: A Voxel-Based Dosimetry Method for Targeted Radionuclide Therapy Using Geant4

Abstract

We have developed the Voxel-Based Internal Dosimetry Application (VIDA) to provide patient-specific dosimetry in targeted radionuclide therapy performing Monte Carlo simulations of radiation transport with the Geant4 toolkit. The code generates voxel-level dose rate maps using anatomical and physiological data taken from individual patients. Voxel level dose rate curves are then fit and integrated to yield a spatial map of radiation absorbed dose. In this article, we present validation studies using established dosimetry results, including self-dose factors (DFs) from the OLINDA/EXM program for uniform activity in unit density spheres and organ self- and cross-organ DFs in the Radiation Dose Assessment Resource (RADAR) reference adult phantom. The comparison with reference data demonstrated agreement within 5% for self-DFs to spheres and reference phantom source organs for four common radionuclides used in targeted therapy ((131)I, (90)Y, (111)In, (177)Lu). Agreement within 9% was achieved for cross-organ DFs. We also present dose estimates to normal tissues and tumors from studies of two non-Hodgkin Lymphoma patients treated by (131)I radioimmunotherapy, with comparison to results generated independently with another dosimetry code. A relative difference of 12% or less was found between methods for mean absorbed tumor doses accounting for tumor regression.

Quantification of internal dosimetry in PET patients: individualized Monte Carlo vs generic phantom‐based calculations

“…32 The latter, based on Fortran, presents significant speed advantages over other Monte Carlo platforms in voxelized geometries. Others were developed ad hoc using opensource Monte Carlo collaborations, like VIDA 19 or RAY-DOSE, 33 that implement a patient-specific dosimetry Medical Physics, 47 (9), September 2020 calculation with Geant4. Recently, the platform RAPID has been introduced, 34 a patient-specific Geant4-based dose calculator for molecular radiotherapy, which calculates on the CT of the patient, with sources constructed from PET/SPECT images.…”

Möglichkeiten zur Verbesserung der Dosimetrie und Therapieplanung in der Molekularen Radiotherapie durch maschinelles Lernen

“…Die [52,53]. In der phantombasierten Dosimetrie werden die Lage, Masse, Form und Absorptionseigenschaften der Organe basierend auf Populationsdaten (vor)definiert [54].…”

Beta-Minus Emitters Dose Point Kernel Estimation Model Comprising Different Tissues for Nuclear Medicine Dosimetry Applications

“…Furthermore, the dose can also be expressed by [12] (5) from equation (5) it is observed that !Q = Y E " Q r ;…”

“…Numerically, it can be inferred through Monte Carlo (MC) simulations [4,5], and analytically it can be derived from S values tables [6,7] or by the Dose Point Kernels (DPK) convolution [8,9] taking into account data from media and radionuclides involved. When performing dosimetry at organ level, it is customary to introduce some approximations like assuming uniformity in the activity distribution within the source regions and/or homogeneous tissue distribution on treated patient region.…”