Internal radionuclide radiation dosimetry: a review of basic concepts and recent developments

Area of Science:

• Medical Physics
• Nuclear Medicine
• Radiation Dosimetry

Background:

• Internal dosimetry traditionally uses model-derived organ dose estimates for nuclear medicine diagnostics.
• These estimates, while adequate for population risk assessment, lack accuracy for individual patients due to anatomical and kinetic variations.
• The increasing therapeutic use of internal radionuclides necessitates more precise dose calculations.

Purpose of the Study:

• To review historical and emerging methods for internal radiation dosimetry.
• To discuss techniques for calculating patient- and position-specific dose distributions.
• To address dosimetry considerations for sensitive populations.

Main Methods:

• Review of fundamental quantities and units in radiation dosimetry.
• Discussion of established methods like the MIRD schema.
• Exploration of advanced techniques: dose point-kernel convolution, Monte Carlo simulation, and voxel S factors for nonuniform dose distributions.

Main Results:

• Traditional methods provide adequate population-average doses but are insufficient for individualized therapy.
• Newer methods enable more accurate, patient-specific dose estimations.
• Specific dosimetry approaches for sensitive groups like pregnant women, nursing mothers, and children are being developed.

Conclusions:

• Radiation dosimetry in nuclear medicine is transitioning towards patient-specific calculations to support therapeutic applications.
• Advanced computational techniques are key to achieving accurate, non-uniform dose distribution assessments.
• Accurate dosimetry is essential for optimizing therapeutic efficacy and minimizing risks, especially in vulnerable patient groups.