Kidneys lite up. Kidneys lite up normally on pet scan. What your body doesn't use. ..You pee out.
Not necessarily so. It could other stuff. Good luck.
Biopsy. What was biopsied between your lung and kidney... your adrenal gland? Depends and the CT appearance and how high the metabolic activity was on PET. Glucose uptake on PET does not necessarily mean cancer. Inflammatory and infectious conditions can also take up glucose. Need more history.
Quite possible. If not an infection.