My husband was recently diagnosed with stage 3b inoperable lung cancer. His treatment is chemo and radiation in combination. So far so good with the treatment but he has had a problem with severe swelling of the feet and ankles since before he was diagnosed, well before he started treatment. His oncologist has given him lasix and it is not helping at all. No one seems to know what is causing this . When I have ressearched this type of swelling and all that shows up is liver cancer. During a CT cysts showed on his liver but nothing showed in the PET scan. Please advise???