My dad had esophageal cancer and he had both a CT and PET scans, I believe they do PET scans because they show more, maybe they wanted to be thorough to make sure they know exactly what is going on rather than give out information that could be false. I hope you are getting on with chemo ok, my dad struggled a bit as he was having radio at the same time.
I wish you all the best and hope you recieve good news from your results, waiting is the worst.
