Last update May 28, 2019
The metastable Technetium 99 (Tc-99m) is a radioactive isotope that emits gamma radiation. Its half-life of radioactive decay is 6.0 hours.
After radioactive labeling with a sodium pertechnetate (99mTc) solution, the technetium pertechnetate solution (99mTc) obtained is used in thyroid, salivary, cerebral, cardiac, vascular, lacrimal scintigraphy and ectopic gastric mucosa localization (obscure gastrointestinal bleeding).
Between 0.82% (Tc 99m pertechnetate blocked, with a T½ of 5.2 hours) and 10% (Tc-99m pertechnetate not blocked, with a T½ of 3.4 hours) of the administered dose is excreted in breastmilk (Leide 2016, Liepe 2016).
Breastfeeding interruption periods or avoiding close contact are calculated so that the infant is not exposed to more than 1 millisievert (1 mSv = 0.1 rem) of radiation (ARSAC 2019, US.NCR 2016, ICRP 2008, Stabin 2000 ).
An adult receives between 5 and 10 mSv annually from environmental radiation.
Breastfeeding should be discontinued after the test for a period that depends on the dose administered: 30 hours for doses ≤ 80 MBq and 57 hours for ≥ 800 MBq according to ARSAC 2019 p51.
Other autors and agencies (Mitchell 2019, USNRC 2016 Tabl U.3) give shorter interruption times: a maximum of 24 hours for ≥1,100 MBq.
In the meantime, milk should be expressed and, instead, milk previously expressed and refrigerated before the test can be given.
Milk expressed after the test can be frozen and used after 10 radioactive half-lives: 10 x 6.0 = 60 hours = 3 days (Hale 2017, page 2019).
It is not necessary to avoid close contact with the infant (Mountford 1999).
We do not have alternatives for Technetium 99m Pertechnetate.
Suggestions made at e-lactancia are done by APILAM team, and are based on updated scientific publications. It is not intended to replace the relationship you have with your doctor but to compound it.
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