Related Experiment Video
Updated: Oct 24, 2026
A Whole Body Dosimetry Protocol for Peptide-Receptor Radionuclide Therapy (PRRT): 2D Planar Image and Hybrid 2D+3D SPECT/CT Image Methods
Published on: April 24, 2020
Enhancements and reference internal dosimetry data for the MOBY whole-body computational phantom of the laboratory
Natalia Carrasco-Rojas1, Robert J Dawson2, Chansoo Choi3
1Medical Physics Program, College of Medicine , University of Florida, 1275 Center Drive, Gainesville, Florida, 32611, United States.
Objective:
Computational phantoms play a crucial role in preclinical studies, particularly for internal dosimetry applications. While the mouse whole-body (MOBY) phantom has been widely used in Monte Carlo radiation transport simulations, several anatomical limitations restrict its dosimetric accuracy. This study introduces enhanced tetrahedral mesh-based MOBY phantoms, in male and female version, featuring refined skeletal structures, improved anatomical representation, and an extended and standardized blood distribution model to support small animal dosimetry.
Methods:
The MOBY polygon mesh representation served as the foundation for phantom development. Using the 3D modeling software, Blender, organ and skeletal structures were refined to eliminate mesh intersections while preserving anatomical integrity. The skeleton was segmented into cortical, spongiosa and medullary cavity regions, and a spinal cord was incorporated into the vertebral foramina. The male model was finalized by adding a prostate and subsequently modified to create the female counterpart by replacing male-specific structures with the uterus and ovaries. Additional anatomical refinements included lymph nodes, Peyer's patches, bronchial wall and primary blood vessels, with organ-specific blood volumes calculated for estimating bulk tissue densities. Each phantom was rigidly scaled to yield six phantoms of different total body mass for each sex.
Results:
A total of twelve anatomically enhanced MOBY phantoms were developed in tetrahedral format. Monte Carlo radiation transport simulations were performed and SAFs and S-values for different radionuclides were computed, establishing a robust dataset for preclinical radiation dosimetry for inclusion in the MIRDcalc software code.
Conclusions:
The refined MOBY phantoms provide a critical advancement in preclinical dosimetry by incorporating sex-specific anatomical details, an improved skeletal model, and enhanced organ-level dose assessments. These phantoms will facilitate dose-response radiopharmaceutical research and support the integration of murine dosimetry models into human dose estimation frameworks.
