A new analytical method for estimating electron-absorbed fractions in soft-tissue biological volumes

Area of Science:

• Medical Physics
• Radiation Dosimetry
• Radiobiology

Background:

• Estimating electron-absorbed fractions is crucial for internal dose assessment in biological tissues.
• Existing methods often require complex simulations or are limited in scope.
• A need exists for efficient analytical tools to calculate absorbed fractions in diverse biological geometries.

Purpose of the Study:

• To develop a novel analytical methodology for estimating electron-absorbed fractions in soft-tissue biological volumes.
• To extend the methodology from spherical to ellipsoidal geometries.
• To provide a simplified and effective tool for internal dose calculations in radiobiology and environmental dosimetry.

Main Methods:

• Developed a size rescaling procedure based on electron Continuous Slowing Down Approximation (CSDA) ranges.
• Applied the rescaling method to existing datasets of electron-absorbed fractions in soft-tissue spheres.
• Demonstrated the possibility of describing rescaled data with a single 'universal curve' and proposed an analytical formula.

Main Results:

• A universal curve was identified for rescaled electron-absorbed fractions.
• A simple analytical formula was derived, dependent on a single parameter (rescaled radius).
• The method was successfully applied to estimate internal doses for non-human biota.

Conclusions:

• The developed analytical methodology offers an effective tool for calculating electron-absorbed fractions.
• The method is applicable to various soft-tissue bio-volumes relevant to different organisms and organs.
• This approach simplifies internal dose estimation, enhancing radiation safety assessments.