Camille,
I'm sorry for any concerns with the PET scan. Have they done a biopsy? As you know, or don't, no scan can prove cancer 100%, only a biopsy can. I've been in your shoes dozens of times, and scans light up (SUV) like a Christmas tree, and are highly sensitive, for the good and bad, especially post treatment, in your case surgery when there can be false positives. Even still, it's not uncommon for patients to be treated further, and many here were, including myself.
Curious as to the area of concern on the PET scan, and the doctors thoughts, and plan moving forward?