Photon dose conversion coefficients for human teeth in standard irradiation geometries

Area of Science:

• Medical Physics
• Radiation Dosimetry
• Computational Biology

Background:

• Accurate estimation of radiation dose to human teeth is crucial for radiation protection and medical imaging assessments.
• Existing dosimetry models often lack detailed tooth-specific data, necessitating specialized calculations.

Purpose of the Study:

• To compute photon dose conversion coefficients for human tooth materials across a range of energies (0.01-10 MeV).
• To assess the influence of radiation source characteristics and tooth location on dose absorption in enamel.
• To provide conversion factors for relating absorbed tooth dose to organ dose or air kerma for occupational dose reconstruction.

Main Methods:

• Utilized the Monte Carlo method with the 'Golem' human voxel phantom, featuring a newly defined tooth region.
• Employed a modified version of the EGS4 code for precise dose calculations.
• Calculated dose responses for 30 tooth cells, including buccal and lingual enamel layers, under various radiation field conditions.

Main Results:

• Computed dose conversion coefficients exhibit strong dependence on photon energy and radiation source geometry.
• Dose response shows weaker dependence on the location of enamel voxels within the tooth.
• For isotropic and rotational fields, enamel dose is largely independent of tooth sample location.

Conclusions:

• The calculated coefficients enable conversion from absorbed tooth dose to organ dose or integral air kerma.
• Integral conversion factors are significantly influenced by photon energy and angular distributions, vital for occupational dose reconstruction.
• Findings provide essential data for improving radiation dose assessments in dental and occupational settings.