Eric
PET =Perhaps Effacious in Theory
I know your fear, but here is my true story on PET/CT scans. In retrospect it's funny and the punchline is that PET scans scores like yours are probably nothing at all.
My MRI in 1/08 was clear but my world collapsed when my PET/CT in 5/08 came back with SUV scores of 4.5 on the RIGHT side of my tongue base and the impression was "metatastic disease cannot be totally excluded". The cancer had been solely on the LEFT side (tumor and lymph nodes). I panicked and my ENT's palpitations did reassure me. I complained to the head of the PET dept and he reviewed it and said it was probably postradiation changes. The PET/CT in 10/08 showed the RIGHT side of the tongue had skyrocketed to SUV of 5.7 but a reassuring impression of "this finding less likely represents in my opinion recurrence of cancer" So when my MRI in 1/09 came back "imaging findings: recurrence of LEFT tongue neoplasm..", I was crushed. Major surgery a month ago and pathology report confirms it was the cancer back again
So both my PET/CT were not only false positives, they both completely missed the recurrence. My ENT surgeon looked long and hard at my Right side when I was spread open and could find nor see nothing out of the ordinary.
It was my ENT who first got worried in December 08 on feeling my tongue. It's hard, I know, but take a deep breath and relax. Have your ENT rigorously examine you and go with that.