I'm posting for another LLL Leader.  She's been contacted by the mom of a 5
month old.  Mom has a growth on her thyroid.  Dr wants to do an "uptake and
scan" using I-131.  He says he doesn't want to biopsy, because of the risk
of removing normal tissue.  Mom has been told she must wean for 30-50 days.

My sources say:

The more she pumps the faster she'll get rid of the radioactive material,
and she would probably need to suspend bfing for 2-14 days.  Milk can be
tested.  (Breastfeeding Answer Book p 518-19)

After a 30 microcurie dose, 24 hr may be adequate to pump and discard.
Excretion by breast may alter validity of test results.  (Lawrence 353-54)

Half-life of I-131 is 8.02-8.1 days.  I-131 is present in milk 2-14 days.
Moms should either wean well ahead of time or pump and dump, to reduce
breast exposure to radiation, since it concentrates in milk (about 28
percent of total dose).  In one study, weaning for 50-52 days was
recommended.  (Hale 310-11)

Questions:  Is there any other (shorter half-life) substance that can be
substituted?  Is there another equally reliable way of evaluating the
growth?  Is immediate testing important?

Diane Wiessinger, MS, IBCLC, LLLL  Ithaca, NY