Percentile-specific computational phantoms constructed from ICRP mesh-type reference computational phantoms (MRCPs)

Area of Science:

• Radiological Physics
• Computational Phantoms
• Radiation Dosimetry

Background:

• International Commission on Radiological Protection (ICRP) Task Group 103 developed new mesh-type reference computational phantoms (MRCPs).
• MRCPs offer advantages over previous voxel-type phantoms, including deformability for various body sizes and postures.
• Existing phantoms may not accurately represent diverse populations in radiation dose assessments.

Purpose of the Study:

• To create percentile-specific computational phantoms representing Caucasian populations.
• To evaluate organ dose differences using these new phantoms compared to standard MRCPs.
• To assess the impact of body size variations on radiation dose from environmental contamination.

Main Methods:

• Deformed MRCPs to generate 10th, 50th, and 90th percentile phantoms based on anthropometric data.
• Scaled phantoms axially and transversally, followed by manual adjustments for precise anthropometric matching.
• Implemented phantoms in Geant4 Monte Carlo code to calculate organ doses from a cesium-137 source.

Main Results:

• Organ doses for the 50th percentile phantoms closely matched those of the standard MRCPs.
• Significant differences in organ doses were observed for the 10th and 90th percentile phantoms.
• Smaller phantoms (10th percentile) generally received higher organ doses than larger phantoms (90th percentile).

Conclusions:

• Percentile-specific phantoms are crucial for accurate radiation dose assessment in diverse populations.
• Body size significantly influences organ dose calculations, particularly in static radiation fields.
• The study validates that smaller individuals absorb higher radiation doses from environmental sources.