Reconstruction of a human skull calibration phantom using bone sections from an 241Am exposure case

Area of Science:

• Environmental Medicine
• Radiological Health
• Nuclear Physics

Background:

• Accurate in vivo measurement of skeletal americium-241 (241Am) is crucial for assessing internal radiation exposure.
• Existing calibration methods require reliable phantoms that mimic natural radionuclide deposition in bone.
• The United States Transuranic Registry sought a calibration structure for 241Am skeletal content determination.

Purpose of the Study:

• To reconstruct a human skull phantom for calibrating in vivo measurements of 241Am.
• To estimate the skeletal burden of 241Am based on deposition patterns in bone matrix.
• To evaluate the phantom's applicability for assessing 241Am burdens.

Main Methods:

• A human skull with a known 241Am deposition pattern was sagittally divided.
• Radiochemical analysis was performed on sections of the skull to determine 241Am activity.
• The skull was reconstructed using the analyzed side and a control skull, embedded in tissue-equivalent material.

Main Results:

• The activity content of the right side of the skull was estimated to be 307 +/- 4 Bq (8.3 +/- 0.1 nCi).
• A functional skull phantom was successfully constructed.
• The reconstructed phantom demonstrated potential for calibrating 241Am skeletal burden measurements.

Conclusions:

• The reconstructed human skull phantom is a viable tool for calibrating in vivo measurements of 241Am.
• This phantom aids in accurately estimating skeletal burdens of 241Am following accidental intake.
• The study provides a method for creating realistic calibration phantoms for internal dosimetry.