Development of skeletal systems for ICRP pediatric mesh-type reference computational phantoms

Area of Science:

• Medical Physics
• Radiological Protection
• Computational Modeling

Background:

• The International Commission on Radiological Protection (ICRP) initiated Task Group 103 (TG 103) to develop advanced computational phantoms.
• Existing voxel-type reference computational phantoms (VRCPs) have limitations due to finite resolution and geometry.
• Mesh-type reference computational phantoms (MRCPs) are being developed to overcome these limitations.

Purpose of the Study:

• To develop pediatric mesh-type reference computational phantoms (MRCPs) with enhanced skeletal anatomy.
• To investigate the dosimetric impact of these new pediatric MRCPs.
• To compare the dosimetry of MRCPs with existing VRCPs for pediatric skeletal tissues.

Main Methods:

• Development of skeletal systems for 10 pediatric MRCPs (male/female, ages newborn to 15 years), improving complex and small bone anatomy.
• Computation of average absorbed doses and specific absorbed fractions for active marrow and bone endosteum.
• Comparison of dosimetric results between pediatric MRCPs and VRCPs for various radiation exposure scenarios.

Main Results:

• The developed pediatric MRCP skeletons preserve original topology while enhancing anatomical detail.
• Dosimetric results for MRCPs were similar to VRCPs for high-energy photons (>200 keV).
• Significant differences (up to a factor of 140) were observed for low-energy photons (≤200 keV) and electrons.

Conclusions:

• The new pediatric MRCPs provide a more anatomically accurate representation of skeletal systems.
• The enhanced anatomical detail in MRCPs significantly impacts dosimetry for weakly penetrating radiations.
• These findings are crucial for accurate radiation dose assessments in pediatric populations using advanced computational models.