Tc 99m MDP

The metastable Technetium 99 (99mTc) is a radioactive isotope that emits gamma radiation. Its half-life of radioactive decay is 6.0 hours
After radioactive labelling with sodium pertechnetate (99mTc) solution, the technetium (99mTc) medronate solution obtained is used in bone scintigraphy.

Between 0.01% (MDP blocked, with a T ½ of 5.2 hours) and 0.03% (MDP non-blocked, with a T ½ of 3.6 hours) of the administered dose is excreted in breast milk (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.

The main regulatory agencies which manage radioactive substances and experts consider that breastfeeding can be resumed immediately after a diagnostic test with Tc 99m medronate (ARSAC 2019 p51, USNRC 2016 Tabl U.3, ICRP 2008 p163, Stabin 2000).

Some agencies (ARSAC 2019, ICRP 2008) consider it more prudent to discontinue breastfeeding for about 4 hours, expressing breast milk once and instead offering milk previously expressed and stored in a refrigerator prior to testing.

Milk expressed after the scintigraphy can be frozen and used after 10 radioactive half lives: 10 x 6.0 = 60 hours = 3 days (Hale 2017 p2019).

t is not necessary to avoid close contact with the infant (Mountford 1999).

See below the information of these related products:

• Occupational exposure to radionuclides (Fairly safe. Mild or unlikely adverse effects. Compatible under certain circumstances. Follow-up recommended. Read Commentary.)
• Scintigraphy (Unsafe. Moderate/severe adverse effects. Compatible under certain circumstances. Follow-up recommended. Use safer alternative or discontinue breastfeeding from 5 to 7 T ½ . Read Commentary.)