I too have been told that I have multiple nodes. I was told that having multi nodes is almost always non canceous. My doctor sent me for a PET scan, which can back negative. I will have a repeat cat scan done next month(6 months).
By now, I would hope that you would have seen a thoracic oncologist. Yes, given the doubling time of lung cancer, if that's what you have, 6 months is too great an interval. Get a PET scan to see if there is uptake, and, also, know that needle biopsies can miss the cancer, depending where they penetrate.
Try the Lung Cancer Alliance website--it is the most comprehensive and compassionate website for all things lung cancer.