Human phantom applicability of 3D-printed polylactic acid for X-ray dose analysis: simulation and measurement studies

In recent years, significant research has focused on the fabrication of human phantoms and the evaluation of radiological imaging using advanced 3D printing technologies and diverse filament materials. This study investigates the absorbed dose due to the physical attenuation of polylactic acid phantoms within the diagnostic X-ray energy range, utilizing Monte Carlo simulations and a radiophotoluminescence glass dosimetry system. The phantoms were fabricated with infill percentages ranging from 20 to 100%, which were visually verified through radiographic imaging, and the reference dosimetry depths varied from 10 to 110 mm. Monte Carlo simulations were performed using the Geant4 Application for Tomographic Emission and the Particle and Heavy Ion Transport code System, demonstrating good agreement with experimental results. The average differences between simulations and measurements were 2.6, 2.7, and 3.1% at 80, 100, and 120 kVp, respectively, with uncertainties of approximately 1% under consistent experimental conditions. The energy dependence of absorbed dose as a function of depth was also examined. For the dosimetry system, the absorbed dose exhibited a more pronounced decrease at lower tube voltages and with reduced infill percentages, resulting in an average error of 6.2% compared to simulation results. These findings provide valuable insights into the development of fully filament-based, human-equivalent phantoms and their potential applications in radiation dosimetry using high-density filament materials for various radiation-related devices.