@autumnwarriorsr, that sounds like good news for now! 50% is a good start.
Our lungs are sensitive, and scar tissue isn't out of the question, but it can make reading scans difficult. I have a spot that shows up near my original tumor. At first, they weren't sure if it was cancer, but it hasn't changed in years, so everyone believes that it's scar tissue. Best of luck with your PET!