Hi Julien,
I've never had an accurate PET scan! I've had negative PET scans when I had positive lymph nodes and false positives. My CT scans on the other hand have always been accurate and I now have much more faith in the accuracy of those results than any other diagnostic tests. I've even had FNAs (needle biopsy) done on positive lymph nodes that came back negative!
This probably doesn't help you much but if you if you had a CT scan with the PET it may have shown enlarged nodes with necrotic centres in which case I would go ahead with the ND. (When I had my ND they actually took the suspicious node first and did a frozen section to confirm the cancer before proceeding further)
Are you having your surgery in Adelaide? You sound like you have a great positive attitude!
All the best to you and your family from a fellow Aussie.
Sue