A lesion is an area of abnormal tissue.
A PET scan involves injecting you with a small amount of radio tracer (radioactive glucose sugar solution). Fast growing cells like cancer and those with naturally high metabolic rates like your heart brain and liver show as hotter spots on the scan. The whole procedure takes about an hour and a half though only ten minutes is the scan....It's a bit like CT you would have had earlier.
The dose is tailor made for you and I'm sue you'll get all the info before your appointment.
Try not to worry too much. I had a PET/CT 16 weeks after my RT finished and had the same. It was biopsied and found to be inflammation only. It's quite common for the RT to have hangover effects which is why a lot of trusts delay confirmatory scan till four months after treatment. Even then a lot of them aren't malignancies.
Just shout if you need any more info.
There's a bit about PET/CT in my blog
Dani
Base of tongue cancer. T2N0M0 6 weeks Radiotherapy finished January 2019
