The xenon is of no concern.  It is an inert gas, and I think is not even absorbed by the mother
and thus cannot get to the milk.  Even if it did, orally ingested xenon is not going to do
anything.

The technetium is a problem, because it is radioactive.  However, whether a mother *needs* to
stop breastfeeding is a question of philosophy.  Remember that we often do technetium scans
on babies.  Also, the amount that will get into the milk is very small indeed, depending on the
mother's serum concentration.  Remember too, that the half life of technetium is fairly short,
Hale saying  about 6hours.  It is true that it is absorbed from the gastrointestinal tract, but then
again, this is used for babies sometimes too.

My approach would be to wait 6 hours by which time half the amount of the technetium
would be out of the mother's body.  I would not argue with a mother who says "I want to
breastfeed immediately", but would suggest she nurse the baby just before the injection.  Hale
states 30 hours, but is suggesting this number because then we can be fairly sure by that time (5
half lives) that there will no longer be *any* technetium in the milk.  I think we can accept that
the baby get a little when we weigh the risks to the baby and mother of not breastfeeding,
because stopping a day and a half at this stage of lactation can result in severe problems.

Jack Newman, MD, FRCPC