Re: radiopharmaceutical patient release

[jtowson@nucmed.rpa.cs.nsw.gov.au (Jocelyn Towson)]

 Jerry Thomas wrote
> I would
>believe that 8 hours following administration 0f 150 mCi that a patient
>could vomit 1 mCi.

Vomitus can be a significant contamination hazard for a couple of days
after I-131 therapy for thyroid cancer.  As mentioned in an article by
Halnan on the metabolism of radioiodine (Brit J Radiol (1964) 37: 101-107),
absorption of a liquid dose of I-131 from the stomach is virtually complete
in an hour or two.  Subsequently, circulating plasma iodide is trapped and
secreted by salivary glands and stomach in competion with thyroid and
kidneys: gastric juice and (swallowed) saliva may have thirty times the
iodide concentration of plasma. Stomach uptake is often obvious on scans 2
days post therapy.  Bumpy car or plane trips might not be a good idea for
patients prone to travel sickness!

Jocelyn Towson
Royal Prince Alfred Hospital
Sydney, Australia
jtowson@nucmed.rpa.cs.nsw.gov.au