[ RadSafe ] Cs-137 in-vivo

[Brian Rees]

Is anyone aware of a medical treatment that would leave Cs-137 in an
out-patient?  If so, how much and for how long?

I KNOW that it's typically used medically as an external source, or
in-patient brachytherapy.  I just don't know of any conceivable reason for a
person to have it in-vivo.

Thanks,
Brian Rees