ICRP Publication 140: Radiological Protection in Therapy with Radiopharmaceuticals

Area of Science:

• Nuclear Medicine
• Radiation Oncology
• Medical Physics

Background:

• Radiopharmaceuticals are increasingly vital in cancer therapy, utilizing advanced radionuclides, compounds, and delivery methods.
• Optimizing radiation therapy, including radiopharmaceutical treatments, hinges on balancing tumor control with normal tissue complication probabilities.
• Accurate quantification of radiation doses to both target tumors and surrounding healthy tissues is crucial for effective treatment planning and patient safety.

Purpose of the Study:

• To provide an overview of radiopharmaceutical therapeutic procedures.
• To present a framework for calculating radiation doses in various treatment scenarios.
• To discuss biokinetic parameters, dosimetry, uncertainty analyses, and radiological protection measures.

Main Methods:

• Determining biokinetic parameters through direct measurements of radiopharmaceutical uptake, retention, and clearance.
• Performing pre-therapy absorbed dose calculations using trace-labeled diagnostic administrations.
• Conducting retrospective dosimetry based on activity administered during therapeutic administrations.
• Utilizing uncertainty analyses to assess the reliability and quality of absorbed dose calculations.

Main Results:

• Absorbed dose in radiopharmaceutical therapy is influenced by radiopharmaceutical biokinetics, radionuclide half-life, and administration techniques.
• Pre-therapy and retrospective dosimetry methods, alongside uncertainty analyses, aid in treatment planning and evaluation.
• Effective dose provides a general risk measure for stochastic effects but is not predictive for individual cancer incidence or deterministic effects.

Conclusions:

• Accurate absorbed dose calculation is essential for optimizing radiopharmaceutical therapy outcomes.
• Robust radiological protection measures, including facility design, equipment, procedures, and training, are critical for minimizing staff and public exposure.
• Patient release decisions post-therapy must consider potential radiation doses to the public and caregivers, necessitating clear guidance.