Hahaha... this made me laugh.
My father-in-law had undergone a medical treatment for colon cancer where they implanted a dozen small pellets of radioactive material around his tumor.
Well he & his wife drove to Canada on a trip and crossing the border INTO Canada was no problem.
However, upon trying to re-enter the U.S. at the Border some radioactive detection system went off, an automatic barrier went up in front of their car and soon a dozen armed police were surrounding their car.
Needless to say a 78 yr old man and his wife were a bit shaken by the experience and my father-in-law was questioned for an hour and their car searched/scanned before they were permitted to continue.
I am grateful that our Border can detect this kind of stuff down to the microscopic levels because a terrorist would certainly have more on them than what was in my relative's butt...
Good thing my father-in-law is a totally funny guy and his retelling of the incident had me in stitches for hours.