Technetium Tc 99m Albumin Aggregated and Breastfeeding

Summary of use during lactation

Information in this record refers to the use of technetium Tc 99m albumin aggregated (Tc 99m macroaggregated albumin; Tc 99m MAA) as a diagnostic agent. A US Nuclear Regulatory Commission subcommittee has recommended that nursing be discontinued for 24 hours after administration of all technetium Tc 99m diagnostic products to simplify guidance recommendations, and the manufacturer recommends at least 24 hours of breastfeeding avoidance.[1] Other sources recommend that breastfeeding should be interrupted for 12 to 13 hours after administration of Tc 99m albumin aggregated based on decay data, although one source recommends a discontinuation period of 20 hours after a dose of 200 MBq.[2-7] During the period of interruption, the breasts should be emptied regularly and completely. If the mother has expressed and saved milk prior to the examination, she can feed it to the infant during the period of nursing interruption.[5,8,9] The milk that is pumped by the mother during the time of breastfeeding interruption can either be discarded or stored refrigerated and given to the infant after 10 physical half-lives, or about 60 hours, have elapsed.[6,8,9] Mothers concerned about the level of radioactivity in their milk could ask to have it tested at a nuclear medicine facility at their hospital. When the radioactivity is at a safe level, they may resume breastfeeding. A method for measuring milk radioactivity and determining the time when a mother can safely resume breastfeeding has been published.[10] For nursing mothers who work with Tc 99m substances in their workplace, there is no need to take any precautions other than those appropriate for general radiation protection.[11]

Drug levels in milk and infant serum

Tc 99m is a gamma emitter with a principal photon energy of 140 keV and a physical half-life of 6.04 hours.[1] The effective half-life of Tc 99m MAA averages 4.3 hours (range 2.6 to 7.9 hours).[8]

Effects in breastfed infants

Relevant published information was not found as of the revision date.

Effects on lactation and breastmilk

Relevant published information was not found as of the revision date.

References

1. Dilsizian V, Metter D, Palestro C, et al. Advisory Committee on Medical Uses of Isotopes (ACMUI) Sub-Committee on Nursing Mother Guidelines for the Medical Administration of Radioactive Material. Final report submitted: January 31, 2019. 2019. https://www.nrc.gov/docs/ML1903/ML19038A498.pdf
2. Burkhart M, Cockerham A, Cook J, et al. NUREG-1556, Volume 9, Revision 3. Consolidated guidance about materials licenses. Program-specific guidance about medical use licenses. US Nuclear Regulatory Commission Office of Nuclear Material Safety and Safeguards 2019. http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1556/v9/r2/
3. Leide-Svegborn S, Ahlgren L, Johansson L, et al. Excretion of radionuclides in human breast milk after nuclear medicine examinations. Biokinetic and dosimetric data and recommendations on breastfeeding interruption. Eur J Nucl Med Mol Imaging 2016;43:808-21.26732471 PubMed
4. International Atomic Energy Agency. Radiation Protection and Safety in Medical Uses of Ionizing Radiation, IAEA Safety Standards Series No. SSG-46, IAEA, Vienna. 2018. https://www.iaea.org/publications/11102/radiation-protection-and-safety-in-medical-uses-of-ionizing-radiation
5. ARSAC notes for guidance: Good clinical practice in nuclear medicine. Notes for guidance on the clinical administration of radiopharmaceuticals and use of sealed radioactive sources. 2020. https://www.gov.uk/government/publications/arsac-notes-for-guidance
6. Mitchell KB, Fleming MM, Anderson PO, et al. ABM Clinical Protocol #30: Radiology and nuclear medicine studies in lactating women. Breastfeed Med 2019;14:290-4.31107104 PubMed
7. Stabin MG. Doses from medical radiation sources. https://hps.org/hpspublications/articles/dosesfrommedicalradiation.html. Accessed Nov 6, 2024.
8. Mountford PJ, Coakley AJ. A review of the secretion of radioactivity in human breast milk: Data, quantitative analysis and recommendations. Nucl Med Commun 1989;10:15-27.2645546 PubMed
9. Early PJ, Sodee DB. Principles and practice of nuclear medicine. 2nd ed. St. Louis: Mosby-Year Book, Inc; 1995:1380-1.
10. Stabin MG, Breitz HB. Breast milk excretion of radiopharmaceuticals: Mechanisms, findings, and radiation dosimetry. J Nucl Med 2000;41:863-73.10809203 PubMed
11. Almén A, Mattsson S. Radiological protection of foetuses and breast-fed children of occupationally exposed women in nuclear medicine - Challenges for hospitals. Phys Med 2017;43:172-7.28882410 PubMed