Modeling X-Ray Dose Absorption In Ex-Vivo Pig Knees Using Geant4*

The purpose of this study is to characterize X-ray dose absorption in ex vivo pig knees, used as a model system for studying radiation effects on tendon tissue. Accurate dose quantification in complex biological geometries is critical for bridging physics-based radiation methods with biomedical outcomes. To achieve this, a cone-beam source operating up to 150 keV delivers radiation, with a flat-panel detector enabling imaging and alignment. Unlike prior experiments with cell culture dishes¹, pig knees are heterogeneous and irregular structures, requiring careful modeling of photon attenuation, scatter, and energy deposition. We describe our framework for dose calculation, which combines experimental dosimetry with Monte Carlo simulations using Geant4² to account for tissue composition, irradiator geometry, and beam hardening. This work lays the groundwork for systematically linking radiation physics with tendon biology, with implications for both radiobiology research and translational therapies.

[1]Truong, K., Bradley, S., Baginski, B., Wilson, J. R., Medlin, D., Zheng, L., Wilson, R. K., Rusin, M., Takacs, E., & Dean, D. (2018). The effect of well-characterized, very low-dose X-ray radiation on fibroblasts. PLOS ONE, 13(1). https://doi.org/10.1371/journal.pone.0190330 

[2] https://geant4-internal.web.cern.ch/publications