Welcome Patsy and Doug
I ditto what Amy said, at times during my father's treatment I don't know what I would have done without this website. Do a search under unknown or occult primary and you will find some good information. My father had unknown primary with all the biopsies and CT/PET scans but they didn't find the primary. He too was very healthy prior to the diagnosis and has never smoke or drank. Please feel free to email me privately. Treating an unknown primary means they will radiate a much larger area. Based upon the location of the cancerous lymph nodes in my father's neck they targeted some areas heavier where they thought the cancer might have originated. I was both relieved when they couldn't find cancer anywhere else but also frustrated at the same time not knowing where it started. You will find other OCF members with unknown primary through your search.
Keep posting and again Welcome
Kim