@smithone58
You area still a young man. I am 78 (79 in May). The radioactive tracer portion is to just to get a better look at everything. It is not a dangerous procedure and had been done millions of times. Your body will expel it. It does not stay with you. Sometimes some of them can cause a warm sensation but you will be forewarned.

I have had them on and off for 10 years. I even get them now when they do a echocardiogram. They do a radioactive dye contrast to get better look at my heart and it's functions. I and my wife also get them when doing a certain type of CT.

You are in good hands and that is the major thing here. They are doing tests to see what is going on and then provide the best treatment.