An open source heterogeneous 3D printed mouse phantom utilising a novel bone representative thermoplastic.

Current pre-clinical radiation research lacks standardized quality control protocols for verifying dose delivery accuracy. This deficiency complicates comparisons across different laboratories and experimental setups. Researchers often struggle to replicate complex anatomical structures using conventional calibration tools. That uncertainty drove the need for highly customizable, anthropomorphic models that mimic small animal physiology. Prior research has shown that existing commercial options are often expensive or lack the necessary tissue heterogeneity. No prior work had resolved the challenge of creating accessible, open-source designs for high-resolution anatomical phantoms. This gap motivated the creation of a new fabrication framework for small animal models. Scientists now seek reliable methods to ensure that radiation beams align precisely with target tissues in vivo.

The aim of this work is to present a complete methodology for producing high-resolution, anthropomorphic phantoms for pre-clinical radiation research. Researchers sought to address the lack of rigorous quality standards in small animal dosimetry. They identified a need for accessible, customizable models that accurately reflect complex biological structures. This project focuses on developing tissue-equivalent materials that can be easily manufactured using additive fabrication. The authors intended to provide a transparent, open-source design to facilitate widespread adoption within the scientific community. By creating a bone-equivalent filament, they addressed the difficulty of replicating skeletal density in synthetic models. The study also explores how these phantoms can be validated through CT imaging comparisons. Ultimately, the team aimed to establish a common quality assurance standard for pre-clinical radiobiology experiments.

The team designed a comprehensive fabrication workflow for creating heterogeneous, anatomically realistic models. They employed high-resolution additive manufacturing techniques to construct the internal skeletal and external body structures. A novel thermoplastic was formulated to mimic the specific attenuation properties of bone tissue. Researchers integrated soft-tissue mimicking filaments to complete the structural assembly based on CT scan data. Air gaps were strategically incorporated to represent the lungs within the thoracic region. The review approach involved comparing the geometric fidelity of the printed model against reference animal images. Investigators evaluated x-ray attenuation profiles to ensure the materials behaved predictably under various beam energies. Finally, they assessed the voxel intensity distribution to confirm the phantom matched the biological reference standard.

The strongest finding shows that the phantom achieves sub-millimetre geometric reproduction of the skeleton and body surface. Specifically, the skeletal Distance-To-Agreement is 0.5 mm ± 0.4 mm, while the body surface is 0.7 mm ± 0.5 mm. Key findings from the literature indicate a 6.6% difference in attenuation for the bone-equivalent material in softer beams. This discrepancy rapidly decreases as the radiation beam is hardened, confirming material suitability. Histograms of voxel intensity profiles demonstrate high similarity between the phantom and actual animal images. The results confirm that the model effectively replicates the complex tissue heterogeneity required for pre-clinical dosimetry. These data suggest that the fabrication approach provides a reliable tool for quality assurance. The study confirms that the printed structure maintains anatomical realism across the evaluated imaging parameters.

The authors demonstrate a viable pathway for producing customizable, high-resolution anthropomorphic models for radiation quality assurance. This synthesis suggests that open-source designs can effectively standardize pre-clinical dosimetry across the radiobiology community. The findings indicate that the bone-equivalent material provides sufficient attenuation characteristics for accurate imaging verification. Researchers highlight that the sub-millimetre geometric precision achieved supports rigorous treatment planning and delivery validation. The study implies that utilizing these phantoms reduces variability in experimental radiation outcomes. Authors emphasize that the provided methodology enables laboratories to replicate complex tissue structures without proprietary constraints. The evidence confirms that the voxel intensity profiles closely match actual animal subjects. This work establishes a framework for future improvements in pre-clinical radiotherapy quality standards.