Just been diagnosed with a cancer on my tonsil, wont find out type till monday, however I recieved an appointment for a kidney. Function scan with a radioactive isotope, Rang the hospital today to check date, and was told it was to prior to chemo, which was news to me.  However I have controlled epilepsy and No one seems to care how it may effect my epilepsy, which I take medication for 

what are possible risks?