Radionuclide administration to nursing mothers: mathematically derived guidelines

Area of Science:

• Nuclear medicine
• Pediatric safety
• Radiopharmacology

Background:

• Assessing the safety of radiopharmaceutical administration in nursing mothers is crucial.
• Existing guidelines may lack objective criteria for determining safe nursing resumption intervals.
• Infant exposure to radionuclides via breast milk requires careful consideration.

Purpose of the Study:

• To develop a formula for objective guidelines on radionuclide administration to nursing mothers.
• To establish safe intervals for breastfeeding after maternal radiopharmaceutical exposure.
• To provide evidence-based recommendations for specific radiopharmaceuticals.

Main Methods:

• Derived a formula incorporating infant's critical organ dose, breast milk activity, and milk volume.
• Utilized serial measurements of breast milk radioactivity.
• Calculated dose to the infant's critical organ per microcurie in milk.
• Applied worst-case assumptions for safety estimations.

Main Results:

• A formula was established to guide radionuclide administration to nursing mothers.
• For technetium-labeled radiopharmaceuticals, a 24-hour nursing cessation is deemed sufficient under worst-case assumptions.
• Longer delays are necessary for radiopharmaceuticals with longer effective half-lives.
• Iodine-123 is recommended over Iodine-131 for thyroid studies in nursing mothers.

Conclusions:

• The developed formula offers objective guidelines for managing radiopharmaceutical use in breastfeeding mothers.
• Short-term cessation of nursing is adequate for certain short-lived radiopharmaceuticals.
• Radiopharmaceutical selection (e.g., Iodine-123 vs. Iodine-131) impacts nursing recommendations.
• This approach enhances infant safety during maternal diagnostic procedures involving radionuclides.