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Updated: Aug 8, 2026
09:49
A Whole Body Dosimetry Protocol for Peptide-Receptor Radionuclide Therapy (PRRT): 2D Planar Image and Hybrid 2D+3D SPECT/CT Image Methods
Published on: April 24, 2020
Radiation interactions and internal dosimetry in nuclear medicine
1Department of Radiology, St Luke's Medical Center, Milwaukee, WI 53149, USA.
Summary
Radioactive decay emits radiation, depositing energy and causing a radiation dose in target organs. The Medical Internal Radiation Dose (MIRD) method estimates this internal dose from radionuclides used in nuclear medicine.
Area of Science:
- Medical Physics
- Radiochemistry
- Nuclear Medicine
Background:
- Radioactive decay releases energy via photons or charged particles, influencing radiation dose.
- Radiation dose is defined as absorbed energy per unit mass, dependent on the decaying nucleus and medium interactions.
- Photon interactions (photoelectric effect, Compton scattering) and charged particle interactions are key in radiation dose deposition.
Purpose of the Study:
- To explain the fundamental principles of radiation emission and energy absorption from radioactive decay.
- To detail the mechanisms of radiation interaction with matter relevant to nuclear medicine.
- To introduce the Medical Internal Radiation Dose (MIRD) method for estimating internal radiation dose.
Main Methods:
- Describing energy emission from radioactive decay (photons, charged particles).
- Explaining charged particle interactions (energy transfer) and photon interactions (photoelectric effect, Compton scattering).
- Introducing the Medical Internal Radiation Dose (MIRD) method and its core concepts.
Main Results:
- Radiation dose is determined by emitted energy, absorbed fraction, and target organ mass.
- Key photon-matter interactions in nuclear medicine are photoelectric effect and Compton scattering.
- The MIRD method provides a framework for calculating internal radiation dose using source/target organs, emitted energy, and absorbed fractions.
Conclusions:
- Understanding radiation interactions is crucial for accurate internal dose estimation in nuclear medicine.
- The MIRD method offers a standardized approach to quantify radiation dose from radionuclides.
- Accurate dose assessment using methods like MIRD is vital for patient safety in nuclear medicine procedures.
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