DOSE ASSESSMENT WITH DIFFERENT METHODS AFTER EXPOSURE TO 14C-LABELLED COMPOUNDS

Area of Science:

• Radiological protection
• Internal dosimetry
• Nuclear medicine

Background:

• Accidental internal exposure to 14C-labelled compounds necessitates accurate dose estimation.
• Standard dosimetry models, based on International Commission on Radiological Protection (ICRP) recommendations, are typically used.
• Deviations in excretion patterns can challenge the accuracy of these standard models.

Purpose of the Study:

• To assess the committed effective dose following accidental intake of a 14C-labelled compound.
• To evaluate the applicability of standard ICRP dosimetry models in a unique exposure scenario.
• To develop a case-specific model for accurate dose estimation when standard models fail.

Main Methods:

• Long-term monitoring of urine samples to track 14C excretion.
• Initial dose calculation using generally recommended methods.
• Comparison of measurement data with ICRP model predictions.
• Development and application of a case-specific biokinetic model based on observed excretion functions.
• Integration of decay data to determine the committed effective dose over 50 years.

Main Results:

• Standard ICRP dosimetry models and parameter values were found unsuitable for this specific 14C-labelled compound and exposure situation.
• Measurement data indicated unique absorption and excretion characteristics.
• A case-specific model accurately estimated the committed effective dose based on actual excretion functions.

Conclusions:

• 14C-labelled organic compounds can exhibit unique biokinetic behavior upon incorporation into the body.
• Standard dosimetry models may require significant adaptation or case-specific development for accurate internal dose assessment.
• Absorption and deposition parameters must be carefully considered and validated for specific compounds and exposure conditions to ensure reliable dose estimations.